Avengers 4: Why Marvel CANNOT Replace Captain America Or Iron Man
Replacements are doomed to fail...
Whenever the conversation turns to Marvel's plans for Phase 4 of the MCU and their contingency plan for replacing the veterans who will inevitably retire when the Infinity Saga is done, there's always a vocal element of fans and commenters who KNOW what's going to happen.
Steve Rogers will pass on the Captain Marvel mantle to Bucky (or Sam Wilson at a push), just as he did in the comics, and Tony Stark will either retire the character of Iron Man (through choice or death) or he'll be replaced by a legacy character himself. Or he'll appoint Shuri his spiritual successor, without any of the Iron Man labelling, obviously. Either way, SOMEONE will continue the heroes' legacies just as they have in the comics.
Some people are absolutely sure of this, despite the fact that - despite some Easter Egg hints like Bucky holding Cap's shield all the time - Marvel have done precisely no establishing work for legacy characters. No dead characters have been replaced so far and all we've heard since there was a suggestion that Robert Downey Jr and Chris Evans will retire from the MCU sooner or later is that Marvel would struggle to do it. And that comes from Marvel themselves.
If you're missing the hints in the directors, producers and co-stars saying the actors are irreplaceable, let it be spelled out more firmly. Marvel WILL NOT replace either Downey Jr or Evans directly, and it's precisely because they aren't idiots.
As has also been stated by Marvel's creators, the problem with even entertaining that idea is that the actors so perfectly embody the characters that it's impossible to remove one from the other. Just as Alan Rickman will always be Severus Snape, Mark Hamill will always be Luke Skywalker and Harrison Ford will always be Indiana Jones, Evans will always be Cap and RDJ will always be Tony Stark. It's got to the stage where they've imprinted on each other so much that imagining the character inherently conjures the image of the actor.
Obviously, characters as iconic as Han Solo, Darth Vader and James Bond have been recast (sometimes successfully) but this feels somewhat different because of the very specific way the MCU has been constructed. And prequels don't really count, anyway.
And it's not like Marvel don't know all too well that there are problems with legacy story-telling. They've got years of evidence thanks to the world of comics and they KNOW the pitfalls. Crucially, they know that the Legacy Heroes approach has been far from a rampant success. It's been controversial just as much as it's been applauded and the problem they have with older generation fans is exactly why Marvel Studios won't entertain the idea of recasting.
Or at least why they'd do it a lot more carefully than the comics arm of the business has in the past. Because, as Ms. Marvel writer/co-creator G. Willow Wilson wrote in a blog post not so long ago, a smart, measured approach is the only way to do it, because of the way established fans react to replacements.
When Ms Marvel took off, Marvel inevitably sought to emulate the success by diversifying far more, but they didn't do it particularly well. As Wilson noted, they did it fairly inelegantly:
“This is a personal opinion, but IMO launching a legacy character by killing off or humiliating the original character sets the legacy character up for failure. Who wants a legacy if the legacy is sh*tty?”
And that line is the killer for the MCU Legacy Heroes: because the likelihood is that Marvel Studios will HAVE to kill off Cap and Iron Man when the actors' contracts end, their replacements are already set up to fail. And there's no other choice for Marvel, because that's just how cinema works.
As long as Chris Evans' Steve Rogers remains alive, he will always be Captain America to the first generation of MCU fans. They will always call for him to return, even when there's another actor occupying the title - see the Bourne Legacy for immediate evidence of that. It's precisely why we're getting an Indiana Jones 5 with Harrison Ford, a new Terminator with Arnold Schwarzenegger and why Die Hard 6 will star Bruce Willis. Fans like continuity when they're invested in a brand. It's not rocket science.
The same feeling extends to Evans and Downey Jr and replacing them would hang a weight on their replacements that they would never conquer. They would always be compared (probably unfavourably); they would always be lumbered with even greater expectations; they would be set up to fail. And Marvel Studios don't make decisions that would set their projects back from day one.
So no, unfortunately, it's unlikely we'll see Cap and Iron Man continue in THIS MCU being played by someone else. And if you're unclear on whether the characters will be killed when they leave the MCU, there are two quotes you need to consider at the end here.
Tony Stark:
"A few years ago I almost lost her so I trashed all my suits. Then we had to mop up Hydra. Then Ultron, my fault. And then, and then, and then. I never stopped. 'Cause the truth is I don't wanna stop..."
Captain America:
"I can do this all day."
In the face of adversity, they don't give up. That might be admirably heroic, but it also means they're doomed. And so too would their legacy replacements be. So don't hold your breath for that to happen.