All that should be required is that teachers warn that the content does not reflect modern attitudes.
Classic novel off GCSE list amid racial slurs fear
https://www.bbc.co.uk/news/articles/cge922jn1z8o
It's John Steinbeck's Of Mice and Men - which I thought was a revealing analysis of the US during the depression.
I found that Tom Sawyer & Huckleberry Finn were entertaining children's books.
Though I did read them as an adult.
I can remember encountering a "bull's pizzle" whilst doing Henry IV Part 1 at O'level - 47 years ago.
I would have thought that Shakespeare includes much bawdy content and ethnic slurs.
Banning something because the content is inappropriate today feels like censorship.