For adults or teenagers I agree, but many of Dahl's stories were intended for younger children, and I don't think content warnings or contextual notes help much

For adults or teenagers I agree, but many of Dahl's stories were intended for younger children, and I don't think content warnings or contextual notes help much there. I would oppose editing the stories of for example HP Lovecraft this way, but for children's books, I think it's entirely reasonable.