I didn't think he would have as great market as the media reported. He's 72 and ran his team into the ground. I get that he's Bill Belichick, but his not 59 year old Bill Belichick. You wouldn't want him shopping for groceries so you need a GM too, and one that he approves of. Further, I am sure there's teams the he doesn't want to work for, either. Changing to "his' culture is going to take a bit, and you need buy in from the owner on down thru the leaders in the locker room. I don't think there's a lot of teams that are clamoring for him at this time.
As far as Philly goes, Bill said to Brady, paraphrasing one pre-game "the only thing to cheer in Philly is the national anthem." I don't see that a good fit, nor do I see them dumping their guy now, either.