What happened to Dahl is a travesty, especially coming from one the oldest and most respected publishers of children's books. Perhaps there's been no outcry because this has been going on for years in the U.S., where sensitivity readers have become an industry. It just took the offenses against Dahl to blow the lid off it.
But there's an equally troublesome effect of the sensitivity-reader boom your article doesn't mention: the potential chilling effect on unpublished books. In the U.S., many books are now being vetted by "sensitivity readers" BEFORE they get published or perhaps even bought. Dahl's books might never have made it into print had sensitivity readers existed in his day. Such practices have the potential to foster vast self-censorship by authors who know they won't get published (or tell the truth as they see it) if they violate unwritten taboos.