Personally, I'd really prefer people stop answering questions on Movies & TV with details from the books or comics, because the questions are about the movie canon. I tend to downvote those answers whenever I see them, even if the OP happens to accept it. I also have heard several users point out that they use M&TV instead of SF&F specifically because they don't want to be "spoiled" by extra details from the source material, so I consider it polite to stick to the movies on a site about movies.
Having said that, all of those questions are about the movie versions of those characters. As such, they're clearly on-topic here, so there's no reason to migrate them elsewhere.