I don't think he'd go to Vegas under Josh, although I think Caley was the guy Josh wanted (Belichick blocked him from leaving if I recall correctly), and his contract is up after this year. And the one edge New England would have over Tennessee is a young quarterback that he would get credit for turning around, along with the fact he worked with Mac briefly during the transition to when he took over the coordinator job in Alabama.
That and he has a good relationship with Kraft and he likes the area. But I agree with
@Steve:Section 102 - could very well be to make sure he gets compensated accordingly.