No, copyright expiration. And yes, I know how Disney is at the forefront of efforts to abolish that and how it's ironic that they profit from it in this case, but I doubt they'd have problems paying license fees either.
Disney as a rule do their thing and wait to see if anyone complains, and then, and only then, do they license.
That's a bold claim. Could you site a source or some examples to back it up?
Disney does not own a trademark on Snow White's use in literature (fiction or non-fiction.)