I just don't see BB taking over in Dallas or JJ offering it to him. Jones won't give up control as an owner/gm and BB won't take a HC spot unless he is the defacto GM and HC.
If Dallas fizzles out either in the regular season or again early in the playoffs McCarthy will be out in big D.
JJ has to have the spotlight when at all possible. He and BB may be old enough to compromise. The average tenure of a HC in the NFL today is 3 years. BB could be enticed to go to Jerry's World to get his 15 wins and the all-time win record with the possibility of another championship without Brady or in N.E. Jerry may tolerate 2 years of Bill without getting to the Super Bowl for Bill to set the record while coaching the Boyz.
If not in Dallas, there will be at least 5 new coaching opportunities for BB in 2025. With a year off Bill may be a hot hire for one of those jobs for similar reasons. There will be a lot of fan fare wherever he lands in 2025. Unless his health takes a sharp turn downward I think he will want to return. If he didn't desire to continue he wouldn't have sought the opportunity this year.
Possible landing spots would fall outside of those that were filled this year more than likely. Almost every one of the other 24 teams is open for discussion today until the 2024 season plays out. Is 73 the new 53? Don't sleep on Bill until he turns the lights out.