I might be mistaken about this, but Disney hasn’t released any film on UHD yet, have they?
Assuming they decide to make the plunge someday, perhaps they’ll make a big deal out of it by announcing something exciting like Star Wars to compensate for being well behind the rest of the pack. Again, if I’m not mistaken, they haven’t even been filming (editing?) new movies in 4K as long as the other studios. Is 4K TFA even possible?
Presumably they can render their rotoscopy garbage classic animations ant any resolution they like, if they’re now vector based.