Based on how The Falcon and the Winter Soldier ended, we’ve got a pretty good idea of what the future holds for the majority of the show’s biggest players.
Sam Wilson is now established as the Marvel Cinematic Universe’s Captain America and will presumably keep teaming up with his new best friend Bucky Barnes, while John Walker has been rebranded as U.S. Agent under the employ of Contessa Valentina Allegra de la Fontaine, who looks set to spring Zemo from The Raft and begin putting the Thunderbolts together, while the Dark Avengers have also been heavily rumored.
However, a new theory puts forward the argument that Walker could be the American-themed hero to join the next iteration of Earth’s Mightiest Heroes at the expense of Sam’s Cap, and it does at least have a basis in MCU canon. After all, the Sokovia Accords mean that the Avengers aren’t autonomous anymore, and have to answer to the United Nations.
By that logic, there’s no reason why the Contessa or perhaps even Sharon Carter’s Power Broker couldn’t utilize their network of contacts to have U.S. Agent added to the lineup the next time the Avengers are forced to assemble to benefit own nefarious means, leaving Sam out in the cold. It might have been rushed, but Walker did at least get something of a redemption arc during The Falcon and the Winter Soldier‘s finale, and up until he bludgeoned a man to death, he’d been an exemplary solider who followed all the orders given to him throughout his adult life to the letter.
As ScreenRant explains:
Rather than build an entire team of super-powered characters, Val’s goal could be to just have one superhero under her thumb. If she can arrange for Walker to join the Avengers, he could take Captain America’s old spot on the team, and possibly even serve as their leader. Sam Wilson may be the new Captain America, but there’s no guarantee that leading or even serving with the Avengers is something that’s on the horizon for him. It could actually be Walker who gets this job in the MCU’s future. This could happen in an upcoming Disney+ show, like Armor Wars or Secret Invasion. Alternatively, it could be saved for Captain America 4 or The Avengers 5.
Of course, Bucky and Walker are the only active super soldiers left alive that we know of with the exception of the elderly Isaiah Bradley, so the latter is still a valuable asset if deployed correctly, although that’s entirely dependent on who ends up pulling his strings.