The ending of Thunderbolts* shocked the entire world by revealing that the team of misfits and anti-heroes is now The New Avengers — an idea that Sam Wilson doesn't approve of. As easy as that, audiences learnt that conflict is brewing in the Marvel Cinematic Universe. Tensions are at an all-time high, and there is a lot of distrust among those who should be on the same side, just like it happened in Captain America: Civil War. In a time when every hero would be supposed to come together to fight Doom, it seems we'll see different uncoordinated teams, each trying to do their own thing.
It was recently reported that Avengers: Doomsday will feature "at least" three different Avengers groups. One of them will be The New Avengers (as revealed by the movie's casting announcement), while another is heavily suspected to be the Young Avengers. After all, the post-credits scene of The Marvels showcased Kamala Khan recruiting Kate Bishop for a new group of super people (oh, and we also have that leaked concept art, which confirms they are set to make their appearance soon).
Last, but not least, Sam Wilson was tasked with recruiting members for "the official" Avengers, and we might finally know who will answer his call.

Hulk, Captain Marvel, and more will be a part of Captain America's Avengers
According to reliable and renowned insider Alex Perez (via The Cosmic Circus), Bruce Banner, Wong, Carol Danvers, Shang-Chi, and Joaquin Torres will be a part of Captain America's team, with She-Hulk being a likely candidate as well. This line-up makes sense, considering what we've seen of these characters in the MCU so far.
Sam directly recruited Falcon at the end of Captain America: Brave New World. Furthermore, audiences witnessed how Wong, Hulk, and Captain Marvel came together to discuss the technology powering Shang-Chi's rings in the post-credits scene of Shang-Chi and the Legend of the Ten Rings. All of these heroes have pre-existing connections, as Bruce is also likely to try to recruit his cousin Jennifer Walters for the occasion. As simple as that, the new iteration of "the official" Avengers will come to be. Now the question becomes: What will be the differences between all these different superhero groups, aside from their respective line-ups?
According to scooper Cryptic HD QUALITY, "very few heroes [will have] real knowledge or intel about the Multiverse or incursions". The post-credits scene of Thunderbolts* already hinted towards this idea, as Yelena Belova mentioned that there's a "huge space crisis" that nobody is telling them about. On the contrary, it will be really likely that Wong's expertise about the multiverse, coupled with Captain Marvel's space knowledge, will give the official Avengers the upper hand.
Avengers: Infinity War already showcased what happens when Earth's Mightiest Heroes are divided into different groups, with each one fighting the same battle on different fronts. Thanos was able to claim victory, and half of the life in the universe was turned to dust along the way. Similarly, this disconnection between all the recent MCU teams may give Doom the chance to accomplish his goal and create Battleworld. And that's without taking into account that a possible fourth team might also enter the scene soon.
Daredevil: Born Again concluded with Matt Murdock realizing that he'll need to form an army if he wants to take the Kingpin down. Furthermore, it was recently announced that Krysten Ritter will be back as Jessica Jones in the show's second season. All signs seem to indicate that the Defenders will reunite once again after a nine-year hiatus, which couldn't be any more exciting. Unfortunately, it seems they will also be in the dark in regards to what's happening to the multiverse, being unable to do anything but attempt to protect New York citizens once the incursions start to tear reality apart.
Hopefully, every active MCU hero (along with guests from all around the multiverse) will be able to come together just in time for Avengers: Secret Wars to deliver the greatest action sequence in superhero cinema. There's no denying that the highly anticipated crossover can't come soon enough.
Avengers: Doomsday will be released on December 18, 2026.