That is still a crap shoot. I hope his legacy is well-protected, but you could still end up with a Dr. Seuss situation. Or Tolkien for that matter. I get it that Christopher hated the movies, but they were done with great respect and love. The moment he passed away, however, Amazon descended and began their... what I can only describe as rapine.
I wouldn't be surprised if he sets up a trust to control the rights to prevent that from happening.