B) The Pats are worried about retaining him beyond next year when he becomes a FA (and we'd lose him for nothing).
All things considered it's probably best to part ways now.
Not really.
If we hold onto him this season as per his contract next season we could realistically slap a franchise tag on him which would land us two first round picks for the player if we don't match any offer he receives.
At least that way we get to see Brady in year 40 and assess where he's at before parting ways with JG.