In an interview with Gamespot, he had this to say about the upcoming title:
"I've seen actually quite a bit. I've played quite a bit. As somebody who's played all of Miyazaki's games over at least the last decade, this is clearly the most ambitious game that he's done. I mean, y'know, I love his games, but seeing some of the gameplay mechanics stuff that he's tackling, he and the team are tackling this time, [seeing] the setting, working with another creator in terms of story... I love it. I love seeing him challenging himself, he's a good friend of mine, expanding his horizons, I think it's a good thing."
Speaking as a huge Miyazaki fan myself, this is heartwarning and exciting to hear. We also learned that he apparently doesn't want people to be influenced by his presence when they play -- or maybe he just doesn't like watching people be bad.
"When he has me play, I go over, he has to leave the room. I think that's because I'm a bad player, and then when he comes back we'll have a conversation about things that I think. He's so passionate about what he does. It's one of the things I just love about getting to work with him on some of these games and seeing them come to our platform."
To date, George himself has had very little to say about Elden Ring, probably because he knows if he opens his mouth people will immediately bombard him about the Game of Thrones books. But for what it's worth, I'd pick Elden Ring over the next book anyway. Mostly because I don't read Game of Thrones.