It is strange, but perhaps they're expecting a QB to hit waivers from some other team. EDIT: Or not . . . per linked article "Hoyer was impressive in the Patriots' regular-season finale against the Giants, and the Patriots are not expected to trade for or sign another veteran QB."
I don't really like to rely on the slim odds of Brady missing time 2 seasons in a row, though.
My guess is they really had a hard time cutting someone at another position . . . perhaps we carry 5 rbs?
uncredited image stolen from teh intertubes