Who will they replace him with that at the same salary can sell more tickets, concessions and licensed goods?
The Patriots already sell out every game without Tebow. Merchandise sales are mot at the top of Belichick's priority list and he makes the personnel decisions.
I believe they have sold out their last ~200 consecutive home games, dating back to when Kraft first purchased the team (1994 or 1995, I think). They sell plenty of Brady jerseys (and various other players), and I would guess their concession sales are just fine.