Realistically, this is a complicated issue. I can understand wanting to modernize older works (wanting to share something you enjoyed, but struggling because said thing has not aged well), but part of the value of those works is in the view they give of the past.
The important part if this is going to become commonplace, I think, is making sure the process is transparent and the originals preserved; EG, if a book is going to be edited, it needs to be explicit (in the new version) that it was editied, what was edited, and why it was changed. It’s one thing to tweak something so that it can still be enjoyed, it’s another to try to forget it was problematic in the first place.
That all said, I find I agree with Pullman, here; I doubt the publisher is motivated to do this by anything other than sales. Let new authors find their place, instead of whitewashing the works of dead men to turn a quick buck. /shurg