Ban is a very loaded, and more than slightly unfair, word to use in this situation.
The Department of Education have changed the list of books to be studied at GCSE. Some have gone out, some have come in. Syllabi change all the time. To declare he is in any way banning books is a very politically motivated use of language, and an absurd way to view the situation.
We read To Kill a Mockingbird at GCSE. I thought it was a good book, but I scarcely think it unthinkable a GCSE reading list could be compiled without it.