I get where they're coming from though. Like it's been something like 8 or 9 years since the last book? And he's started another series since then. And his health is crap, but he made it a provision of his will that any and all notes are to be burned and no one else can finish his books.
But like. I get that he doesn't "owe" anybody anything. If there's no more books there's no more books. Period. Boohoo, it just didn't happen, enjoy what you have. But at the same time being a professional writer, that's pretty unprofessional to just leave it like that and not even apologize to your fanbase.
or say "well I put everything into the tv series now" and then later be like "Argh but they changed everything in the tv series so that's not the real plot"