GL has enough bank that he doesn't NEED his baby anymore, I'm not sure why he sold it -- it certainly wasn't for the fans maybe it was to wash his hands of it and be exempt from any responsibility of the franchise.
I just have to add that this can be both good and bad; the bad I've already stated -- you don't really NEED movie-confirmed canon to enjoy a book. The good, a much needed breath of fresh air into the franchise that for years focused solely on The Clone Wars and viewers aged 10 - 14. Hopefully this new trilogy will gather old fans and new fans alike, while working with a new and original story for the new movie(s) (no I don't care if I don't see Thrawn/Yuzzahn Vong/Legacy stories etc. on the big screen)