But real talk, Marvel must have faith in his defense because they haven’t made any decisions yet
Maybe.
It's such a difficult thing to gauge for a lot of different reasons.
As far as the ol' switcheroo goes, Marvel's biggest change was Norton's Hulk followed by Terrance Howard's Rhodey (Not counting Thunderbolt for obvious reasons.)
That was done before the unimaginable runaway sucess of Iron Man ignited the pop cultural phenomenon of the MCU.
Kang's the new big bad so the whole universe's narrative conflict lies with him.
That said between CGI, comic books
rules, and the fact that variants don't have to look identical (by definition makes sense but also SEE: LOKI.) means there's always resources for creative alternatives and improvisation.
While the real life consequences pale in comparison, this is probably the most delicate real world situation Marvel has had to navigate since Boseman's untimely passing.
Someone at Marvel likes Majors.
Especially in this climate.