Without being an expert in Marvel at all, I think you are likely to be correct about Wakanda--the scale, materials, and scenery are likely to be achievable in a theme park setting (if my memory from the movies is correct).
I would hesitate to agree about Latveria being a desirable locale to recreate in a theme park. Even if the architectural scale is doable, would you really want to spend time having fun in a recreation of a repressive totalitarian country? That is part of why Star Wars: Galaxy's Edge is less than fully successful. Hogsmeade it is not.
I fact, I think Six Flags' various DC-villain themed coasters are instructive here. Sure, you can recreate the Joker's warehouse, a dangerous neighborhood of Gotham City, or Mr. Freeze's lair. But when you do, you've created a fairly repellant space. Not the kind of place you want to linger in (Halloween Horror Nights is a fair reputation of this point, but I maintain that it is a niche product.)
Marvel Super Heroes could inspire many great rides, but I don't think they make a good source material for a Harry Potter-style immersive land, either for the lack of visual uniqueness, scale, or unpleasantness.