The real answer is boring. Think about the legal precedent that would be set, this would be seen as condoning anyone to go out, market and accept money for a representation of their IP without asking for permission beforehand, no legal team worth their salt is going to allow that. They don’t want to reward someone for doing things the wrong way from a legal standpoint. There’s also probably a potential fraud liability here, the same way trademark owners are required to legally pursue copycat brands to prevent customers from being defrauded

There have been no major innovations in film technique for much longer than that, so they make a good point. 10 years is not a long enough interval to call filmed media old, unless someone is quite young and lacks context