Use of gendered language is marginalizing to nonbinary people.
It's easy to figure out why these changes are being made in particular, once you take a position of empathy.
Write new books. Make them as inclusive or exclusive as you want. I just think it's very telling that you hear so much about "erasure" and yet changing an author's words and intent like this is celebrated.
Ask for empathy in a preface, or an introduction, if you have to. Stay the fuck out of Dahl's work. You don't have to like it, but changing it is obscene - Dahl is not alive to permit these changes, and would probably be horrified. They're his fucking words.