Marvel Studios' Phase 4 is setting up a New Avengers Team and subsequently a Champions team
Phase 4 initially seemed to focus on Multiverse events as seen in Loki, No Way Home and Multiverse of Madness; following the latter, Marvel Studios seems to be setting the multiverse aspects aside for Phase 4 in preparation for Secret Wars project down the line which will be helmed by the Russo Brothers (the earliest we can expect to see Secret Wars until probably 2025 or 2026). The other big push for Phase 4 has been introducing new heroes such as Shang-Chi which has already eluded to be getting a sequel eventually. The Fantastic Four movie which was to be directed by Jon Watts (but he has just left the film) with a release date set between 2023-2024. We got a new team movie in The Eternals, although it appears highly unlikely they will get another film and it's already been addressed that we will likely see these characters appear somewhere eventually. Then we have the introduction of legacy heroes based on the original 6 Avengers, starting with Sam Wilson being the new Captain America, Yelena Belova seemingly to become the new Black Widow, Kate Bishop training to be the next Hawkeye, She-Hulk, Riri Williams as Ironheart and Jane Foster's Thor. It almost seems odd that we wouldn't get a new Avengers movie prior to the rumored 3 films making up Secret Wars.... unless their is but it's not solely an Avengers movie.
Ms. Marvel's Disney+ series is set to release in June and unlike other MCU shows they have not labeled it a limited series. Ms. Marvel is one of the few shows that isn't being marketed as a limited series, so it seems more than likely we will get a Season 2 (as long as it does well) so that it can slowly begin to introduce the ideals and characters to create the Champions. I wouldn't be surprised if we get a cameo of Captain Marvel to set up her appearance in Captain Marvel 2. If it's not Captain Marvel, it could very well be Anthony Mackie's Sam Wilson will appear in a post-credit scene and request Ms. Marvel's help in establishing a new Avenger's Team (if not Season 1 at least in Season 2).
The All New, All Different Avengers team had a team of Sam Wilson (as Captain America), Jane Foster as Thor, Vision, Iron Man, Kamala Khan, Miles Morales, and Sam Alexander. It wasn't before long that Khan, Morales, and Alexander left following the 2nd Civil War frustrated by their adult peers, they eventually left the Avengers to create their own team. For the MCU, we could see a similar notion happen in the near future.
Although we may not see this team's conception for at least 3-4 years it appears to be in the cards eventually and will most likely be set up during or right after Captain America 4 (See here for our take on a potential Captain America 4). As we saw in Falcon and the Winter Soldier, Stark enterprises no longer financially supports the Avengers and the team seemingly doesn't exist currently. With the team currently disbanded we will likely see Sam Wilson assembling a new team and of those members it appears Kamala Khan will be joining as the youngest member. Current expectations for the new team are wide open and the only ones we can assume will definitely be on the team is Sam Wilson, Bucky Barnes, Jane Foster's Thor and Kamala Khan. There is also a bevy of other choices for the other 2-4 roster spots such as Shang-Chi, She-Hulk, White Vision, Wanda Maxximoff, Ant-Man, Wasp, Monica Rambeau, Shuri (or whomever else takes up the mantle of Black Panther), Richard Rider as Nova. Those that have been excluded I assume will end up on another team such as the Young Avengers or the Midnight Sons.
What kind of event could bring the Avengers to reunite once again? Enter the Thunderbolts/Dark Avengers movie, with Villains portraying themselves as as the new Avengers. We know that Val is working for some mysterious figure (Dr. Doom?), all that we can confirm is that she is building a team and has at least one current member in John Walker/US Agent and potentially Yelena Belova as well. After an initial confrontation a falling out occurs between Sam Wilson/Bucky Barnes and the Dark Avengers (and/or the Thunderbolts) prompting a fight. After losing the battle Sam and Bucky begin making efforts to restore the Avengers to protect the Legacy of the Avengers.
After establishing the New Avengers Team working to show that the imposters are not the Avengers, it could set up for Kamala to leave the team to create the Champions (more on that below). This is all speculation of course, but considering the next Avengers project is rumored to be Secret Wars which will extend across three films and is likely to deal with the Multiverse characters as well. It seems likely that if we are going to get the Champions (or a Young Avengers team, if not both) for at least 4-5 years but the seeds are being planted now.
We still don't know if the Sokovia Accords are still active but it would appear as though they are not as heavily enforced, if not revoked all together because it has not yet been referenced much since Endgame. Perhaps we could see them reconstructed in a new way that justifies heroic actions, but now instead of restricting all heroes, it only restricts those under 18 from heroics (or at least require an adult mentor). With the most important part of the previous speculated team of Avengers is that it would feature Kamala Khan (Ms. Marvel), who would in this case still be too young to participate (or even if she just became 18). Inevitably setting up her leave from the Avengers in spite of this ruling, so she can then watch over other younger heroes. She searches out younger heroes that don't have connections to any other heroes (thus why Young Avengers are a separate team) so she can form the Champions.
What could the potential storyline be for the Champions?
Although Marvel Studios is unlikely to follow the same storyline as in the comics, the most recent comic run of the Champions is a fantastic story. With the Champions dealing with on going pressure from Kamala's Law, a mega corporation in ROXXON and social media. Kamala's law was created to prevent anyone under 18 from using their powers to act as a hero/vigilante unless they had an adult hero as a mentor, who would be held responsible for their protégé's actions. This irked the team because the Champions were established to separate themselves from the Avengers. The Champions were created to "reclaim and redefine in a classic sense what being a superhero should mean. Rather than seeing the previous generation as these icons that came before them, now they've interacted with them on a one-to-one basis and learned they aren't better or worse than anybody else." -Tom Brevoort - Executive Editor.
The Government created a task force known as Child Hero Reconnaissance and Disruption Law Enforcement AKA C.R.A.D.L.E. designed to arrest any young heroes acting as heroes. Roxxon was apart of this Law as they offered re-education centers for the young heroes that were arrested and forced to go through counseling and activities in order to break down their spirits. The Champions gained the victory by showing the public the results of Roxxon's re-education centers and they are then shut down with Kamala's Law to be reviewed once more.
With Ms. Marvel getting her own series prior to appearing in Captain Marvel 2, it means that Marvel may be looking to build up her story prior to her joining any teams and with that it will position herself as the leader of the team. The rest of the Champions could consist of other young heroes such as Riri Williams as Ironheart, Sam Alexander as Nova, Miles Morales as Spider-Man, Ammadeus Cho as Brawn, Viv Vision (a Synthezoid daughter of White Vision could have recently created) and could also potentially feature the mutant Sooraya Qadir AKA Dust (who can manipulate Sand).
Miles Morales (unlikely but hopeful!):
I have wrote before speculatting how the Champions could come together and how it could still utilizing Miles Morales the same way the Sony and Marvel came to a prior agreement for Tom Holland's Spider-Man. Since Tom Holland has signed on for another 3 films but beyond that, it's unlikely Holland will do any Marvel movies (outside of Secret Wars).
Therefore rumors have surfaced that Sony is looking to cast a live-action Miles Morales. It's not known if Marvel will be assisting with this search but based on how Venom and Morbius movies have been handled, we can only hope Sony will accept the fact they can't make quality (Marvel) movies without the help of Marvel. As I've pointed out before with Olivia Wilde's upcoming Spider-Woman (still betting it will be Gwen Stacy not Jessica Drew) movie she said she doesn't want to say too much and anger Kevin Feige, so perhaps Sony is at least asking Marvel's head boss for advice on the more important characters.
We already know that she will be getting her own series, what we don't know is how connected she will be with the rest of the MCU heroes. We do know that she will first being making an appearence in Black Panther: Wakanda Forever but it seems unlikely we will see her Ironheart Armor just yet. It seems inevitable that Riri will meet James Rhodes (War Machine) because of the connection to Tony Stark but it's more than likely Rhodes is retired at this point, leaving Riri in need of a team to join and without a mentor. It's entirely possible that Sam Wilson could approach Rhodes and ask for him to join the Avengers and Rhodes responds by saying he's retired but recommends Riri take his place.
It was recently announced that a Nova project is currently being worked on by Sabir Pirzada, he is a co-writer of Moon Knight episodes 3 through 6. The question is which Nova will it feature? We saw Thanos destroy the planet of Xandar in Infinity War as the Nova corps sought to fight back against him. We know that Infinity War and Endgame screenwriter Christopher Markus had stated there was at least one plan to include Nova into both movies but he was ultimately cut. The initial idea included Richard Rider surviving the destruction and would include the Xandarian Worldmind which is a sentient computer that contains the collective knowledge and history of Xandar. Although we didn't see it in either film it seemed a shoein that we would see Nova cameo in Guardians of the Galaxy 3 but it has been reported that he was scrapped from the film. It begs the question, is Marvel trying to use Richard Rider or Sam Alexander as their Nova? Based on the fact that he was contemplated twice, Marvel Studios clearly wants to utilize him at some point sooner than later. Here's Kevin Feige's input on when we could potentially see Nova, "If we have a big board with a bunch of characters that have more immediate potential, Nova is on that board.”
It still hasn't been announced whether Nova will be a limited series or movie, but my guess is that it will be a series because if he was going to be his own movie he probably still would've made a cameo or post-credit scene in GOTG 3. To further extend our estimates for the series they ultimately decide to go with Sam Alexander over Richard Rider, you can still introduce both of them. It makes more sense to go with the younger character and then introduce Richard Rider later as potential mentor later in the series as he comes looking for Sam's helmet.
As I've mentioned before in my She-Hulk article and how it could spin-off a new Hulk movie. Amadeus Cho likely exists in the MCU because we saw his mother Helen Cho in Avengers: Age of Ultron. Amadeus is one of the top 10 smartest people in Marvel's history so it seems entirely likely he could create a Gamma Transmitter in order to remove the Hulk from Bruce Banner and/or replicate the Hulk transformation in himself allowing him to become the Totally Awesome Hulk (although he is know referred to as Brawn).
With the White Visions recent restoration in Wandavision, he could be seeking to understand what exactly it means to have someone to care for and care after. Considering White Vision does not have an infinity stone powering him, it totally seems feasible that he could create his own family as he tries to understand why and how Wanda felt about Tommy and Billy. After her creation White Vision, who I fully expect we will see again in the MCU, could bring Viv to Ms. Marvel stating that Viv needs some friends.
Sooraya Qadir AKA Dust:
She could be introduced as one of the first mutants we see in the MCU. Sooraya's character wouldn't need connections to the X-Men either and would fit with the Champions as a way spreading out mutants in the MCU. She could be introduced as quiet and nervous new member of the team, since she's had to conceal her power (or at least hide herself as sand) for such a long time until the Champions or even Kamala herself in her own series, comes to rescue her. Sooraya is also a Muslim like Kamala, the main difference is Dust was born in Western Afghanistan and she is a practicing Muslim, who is devoted to her faith which could create an interesting diatribe between the two.