if he goes to miami it is about revenge and that the issues with boston hurt him.
he wont start there..won't get paid as much..as honestly will have about the same chance at another title
If he goes to Miami, it is because he wants to live in Miami.
When all of his family is in Boston?
I mean, if he likes Miami that much, he could always retire. 
All of his family would move to Miami as well.
Supposedly, he is looking to make his final move right now, and bring his family with him. And I would not begrudge him for wanting to make that move to Miami.
What he doesn't want to do is enroll his kids in school again in Wellsley this year, then get traded in midyear and have to go someplace else, not of his own choosing. And then move again when he retires.
This will be the retirement move IMO.