This is the bigger thing. Belichick as an all time great coach is set in stone.
Belichick's status as unquestionably viewed as the best of all his peers you could compare him to (Walsh, Shula, Reid, Landry, Gibbs etc) is on shakier ground mostly because his post Brady stint was comparable to his Cleveland stint which we gave him the benefit of saying "he grew out of it and got better".
I said this earlier, but a lot of the NFL landscape is already saying "well Reid way better than Belichick without his HOF QB and now that he has one, he's winning rings too". If Reid gets one more or even two more, there's going to be a non insignificant amount of fans and media putting him at the same level or ahead of Belichick. Because the perception is "yeah Bill is a great coach, but what set him apart from everyone else is 19 years with Tom Brady"