The Marvel Cinematic Universe may have earned over $20 billion at the box office, but all four of the franchise’s highest-grossing titles are Avengers movies, so while Endgame may have drawn a definitive line under both the Infinity Saga and the current incarnation of the team, Earth’s Mightiest Heroes are guaranteed to return in some form or other.
With Iron Man and Black Widow dead and Captain America retired, that’s half the original lineup out of the picture already, and Phase Four could see the others follow suit. The Hulk might stick around and be involved with the She-Hulk show, but he’ll remain a supporting character due to rights issues, and there’s already been plenty of speculation that Love and Thunder could end up marking Thor’s last stand.
That just leaves Hawkeye, who we know will be part of the MCU until at least 2022 when his protege Kate Bishop headlines her own Disney Plus exclusive that will push Jeremy Renner into a supporting role. There were rumors that Renner’s personal issues could ultimately hasten his departure, but looking at what’s happening to the rest of the Phase One Avengers, it seems increasingly likely that the plan might have already involved him stepping out of the limelight anyway.
After all, it would make total sense for Clint Barton to act as Kate Bishop’s mentor in the first season of Hawkeye before killing him off, which would remove another of the MCU’s elder statesmen from the board while also giving his successor narrative motivation to step up to the plate and assume the mantle on a full-time basis, especially when she’s always been a key player in the Young Avengers, a team that’s widely assumed to be appearing sooner rather than later.