Following the remarkable journey of Steve Rogers, he has passed on the shield to another hero, Sam Wilson, who got his own series alongside Bucky Barnes in The Falcon and the Winter Soldier. When Sebastian Stan was asked on his return in Captain America 4, the only possible reason if he doesn’t show up would be Anthony Mackie who may keep him out of the movie.
Sebastian Stan attended the red carpet celebration of Pam & Tommy and there, Extra asked him if he would be back on Mackie’s Captain America 4, his response reflects the friendship that they built over the years, "I don't know. I really don't know. I really hope Anthony Mackie doesn't have any say in it because if he says because if he has any say in it, I'm not in Captain America 4. I love him. He's the best, you know that."
The chemistry of Sebastian Stan and Anthony Mackie has been apparent in their shared series, The Falcon and The Winter Soldier, where the friendship of the two really translates beyond the scenes, showing how great friends they are in real life that they don’t have to fake any second of it.
Details on Captain America 4 remains scarce other than there would be a new person to wear the costume of the star-spangled hero and it would be Sam Wilson who finally embraced his destiny as the new Captain America after Steve, himself, chose him to be his successor.
Most of the heroes on the fourth phase of the Marvel Cinematic Universe has been either dealing with the after-effects of Endgame or passing the baton to another and in the case of Sam Wilson, he’s finally retiring his title as The Falcon and he gets to be the new Captain America without having to lose his wings. He even had his own costume by the finale of the series.
As for Sebastian Stan’s Bucky, he remains to be the right-hand man of Captain America, may it be Steve or Sam. He has to deal with his own path, too, possibly embracing the title of the White Wolf in the near future. Plus, both of them found a newfound frienemy with Baron Zemo.
The cliffhanger of The Falcon and The Winter Soldier could be carried on in Captain America 4 where Sharon Carter was revealed to be the Powerbreaker and with John Walker becoming the US Agent after being visited by Contessa Val. The new star-spangled hero would surely have a lot on his hands.
Captain America 4 is yet to have a release date. The Falcon and The Winter Solider is available to stream online on Disney Plus.