Feige had high praise for the Avengers stars while realizing that they may eventually face a tough decision:
”Robert Downey Jr. is Iron Man, and right now I can’t envision anyone else. Chris Evans has embodied Captain America as well as any actor has ever embodied an iconic pop-culture figure like that. I go back to Chris Reeve as Superman as the gold standard, and I think Evans is right there. I couldn’t imagine anybody else. … But you also look to history: We have a new Spider-Man right now who was in our “Civil War” film and is in “Spider-Man: Homecoming,” and the audience has embraced it. And you can look to Sherlock Holmes, James Bond, and Batman as characters that last longer than any one actor playing them. There’s a precedent for it in other franchises that suggests it’s possible.”
It may be hard for fans of the MCU to envision any actor besides Downey Jr. inhabiting the role of Tony Stark/Iron Man. Evans, meanwhile, has set a new standard for portraying Steve Rogers/Captain America as he became the first incarnation of the superhero to see widespread release (and success) on the big screen. If and when the MCU launches a new run of stories featuring these characters, the next incarnations of them will have very tough acts to follow.
As Feige himself stated in the interview, recasting is likely inevitable as the MCU enters new phases and continues to churn out new material. It’s terribly unrealistic to think that Iron Man and Captain America would cease to exist in Marvel movies once Downey Jr. and Evans decide to move on from the roles. There have already been two different actors to star in two different Spider-Man franchises, so as great as certain actors have been in certain roles, no Marvel character should be considered sacred.