100%? Seriously? About something that's purely your own guesswork rather than objectively verified data?
Nothing is ever 100% certain. Even with hard data, there must always be room for doubt and an openness to alternative possibilities.
Why not? Rocket and Groot are purely voice roles for Cooper and Diesel, yet they're credited and touted as full members of the Guardians ensemble. Pedro Pascal gets star billing for The Mandalorian even though it's usually just a voice role. The old prejudice that voice actors are unimportant has faded these days, given how common it's become to cast big-name actors in animated films and other voice roles.
And someone wearing a costume in a Comic-Con panel says nothing about what will happen in the actual movie. They thought it made a cool reveal to have Doom unmask and turn out to be RDJ. There's no basis for assuming it has any meaning beyond the showmanship of the announcement itself.
I've already given multiple examples of the same actor coming back within the same series. Again, you're making the mistake of assuming your perspective as a viewer is the only one that exists. What you watch onscreen for two or three hours is the end result of months or years of the filmmakers and actors working closely together for maybe 16 or more hours a day. Onscreen things like whether two stories are in the same continuity are incidental to that. It's still the same kind of working experience behind the scenes. If a moviemaker knows they enjoy working with an actor over the long haul, if they know that actor can be trusted to do the work reliably, that real-life consideration matters more to them than what imaginary "universe" two different stories are in.
Exactly. Especially when we're talking about a chameleonic character actor like Downey. Anyone who's seen Chaplin or Oppenheimer should have zero doubt that Downey can transform himself so completely that nobody would mistake Victor von Doom for Tony Stark. Especially since Doom almost always has a mask on!
