It'd be less galling if he'd designated some sort of Christopher Tolkien-esque literary executor to tie up the series in the event of his demise. But he's explicitly refused to do that. (I think it's understandable that he has, for various reasons, but it's still incredibly frustrating.)
I volunteer for the position.
Joking aside, I don't see why he wouldn't because he gave the ending away to the show's creators. This move seems hypocritical.
Not really since the show-runners clearly have little-to-no interest in following the books at this point. Beyond which, I suspect he only gave them broad strokes, people have this idea that everything's planned out already to the smallest detail and that seems kinda ridiculous.
