the context is that it wouldn’t been needed before.

Before like in the past? Of course it wasn’t needed in the past. Times change, what is considered offensive evolves. It’s a good thing to have a little side note saying “Just so you’re aware this author isn’t a racist/sexist/homophobic/transphobe. The terms used in book were not considered offensive at the time of publishing and no disrespect or insult was intended”. Including notes like that are pretty important so that we can enjoy older media in the way it was intended and not make important works taboo because they don’t conform with today’s standards.

I’m in my 30s and there’s already a lot of words I used in childhood that are considered offensive now. And I’d put money on the likelihood that some words I use now won’t be considered appropriate within my lifetime. That’s not censorship, it’s progress.