Doomsday isn't confirmed at this stage, but there have been manyrumors pointing towards Evans making another return to the Marvel Cinematic Universe for this

Before Captain America 4, Anthony Mackie had a totally different career plan — one far from superhero stardom. Here’s what he originally wanted.

The spoiler-free set-up: Mackie’s character, a military veteran, counselor and former “Avengers” sidekick named Sam Wilson, has traded in his Falcon alter-ego (and his deep reservations) to finally accept the Captain America mantle.