If they rest the, i.e. suit them up, and not play them, agreed. But if they end up not suiting up at all, I'm sure the NFL tracks injury reports (probable, doubtful, limited) and if personnel end up or playing or not. Then if over the course of a season or a single game for that matter, the numbers don't meet league some type of expected league standards (of which I don't think anyone knows what they are for sure exactly), NE and BB get a nasty phone call asking for an explanation.
Or in other words, consider hypothetically if BB out of the blue just didn't play 7 ,8, 10 or 15 guys on any one given Sunday, and none of the players were at least listed once on that week's injury report. The NFL and the opposing team, to say nothing of the lemming media to follow, would be pretty upset, citing all sorts of possible injury report shenanigans. So, by first listing these players on the injury report, BB, or any coach, have covered their asses, and now have the option (NFL abiding regulation wise) to not suit them up out of the blue without dealing with such red tape variety malarky heaped upon them after the game(s).