This is kind of what I think will happen.NFL would never ban him. They won't even suspend him. They'll just keep fining him and the team. Maybe take away another pick. The 31st or 32nd pick. Won't hurt them and they'll keep finding more ways to cheat.
It's going to be very hard to connect Bellichick to the act. Very hard.
Guessing that taking care of the footballs is given to some low level equipment kid. What are they going to do, put him under oath and make him testify against Bellichick (and the organization) that he was commanded to let some of the air out? Good luck with tat.
These guys are smart... they step right up to the line, look over, determine if they can get caught and tip toe over it.
Don't like it at all... but nothing much will come of it. Certainly no significant actions for the team or Bellichick.