Obviously, the events in Avengers: Endgame –and spoilers — left Steve Rogers with Peggy Carter and Anthony Mackie’s Falcon with Cap’s shield.
Prior to the events in Avengers: Endgame, Chris Evans had talked about retiring from the MCU, having been one of the early actors to sign on the dotted line and join the fold.
More info on how to sign-up for Disney+ ahead of What If’s 2021 release can be found here.
With all of that said, I will note you should never say never in the MCU, particularly when programs like What if? exist.