I'm always skeptical about claims that $MOVIE couldn't be made today that was made in a past decade. Lolita's title character was 3-4 years older than the character in the book in both films. Pretty Baby was very controversial when it came out. (ADDED: And I'd entertain the thought that it might be even harder to make today/be even more controversial.Might be more like HBO material.) Nymphomaniac is a European art film. Whether or not Rocky Horror and Holy Grail would be appealing to modern audiences I don't know but I see no reason they couldn't be made.

In another vein, I've also seen the claim made that Heathers couldn't be made today because of school shootings, yet it was made into a Broadway musical within the past decade.