I think that they should release a document and add it to future printings of the book addressing the background of the Vistrani race and explaining why they wouldn’t do something like it again. Like with old Loony Tunes cartoons, I don’t necessarily think the best approach is to expunge it from our history, but to frame it in a modern context. These racist tropes can be easily propagated in media by writers who have no idea they’re even playing with these ideas and I think a wake up call like “hey, this seemingly harmless stuff that follows is actually a big deal for some audiences” raises awareness better than just rewriting or expunging it.