My first thought is that Jerry gave Rob what he needed this year on D, FA and draft; this offseason, Jerry will give Callahan what he needs for a solid OL and give JG another weapon at RB.
I think he gives JG one more season with a solid D and OL to see what he can do.
However, what not one of us is actually privy to is the locker room. If JG's message has grown stale and his game management has lost the locker room more than we realize, he's GONE. If most of these guys have his back and run through walls for him and speak out for him when the time comes, then he probably stays.
I'd love to hear if Garrett's message is still fresh and building in the locker room.