Not at all. Not saying Brady doesn't know anything about Belichick. But Brady is a player and Belichick is a coach. Brady cannot change his strengths and weaknesses. Belichick can change how he calls a game in one game to throw Brady off. In fact, the hallmark of the Belichick defense is that they adapt to the opponent which it make hard to know his tendencies and weaknesses.
And also Brady only had one year with the current defensive staff calling plays. So he doesn't have much first hand knowledge how Belichick Jr. or whoever is calling plays calls plays.
And again, this thread isn't about who is going to win the game or who is better. It is a narrow question of who gets the advantage in the fact they know each other so well. I say Belichick clearly gets the nod in that category.
There's a flipside to that which is a player like Brady can wake up that morning and be immaculate and there's nothing the other team can do. In principle I agree with you that Belichick more than anyone should be able to gameplan on Brady, but the truth is, Brady can have a day where he just out executes everyone regardless.