I agree with this. However if that happens and Allen does take that next step and plays similar to the way Goff and the Rams did in his 2nd yr, I wouldn't count them completely out for challenging for the division. Of course this is wishful thinking, but if Allen gets the tools he needs with better blocking and continues to play at a high level like towards the end of this past season then the Bills will be putting a lot of points on the board.
I don't expect too much to change with the defense, I still expect them to be playing at a high level anyway, so it will be interesting to see how all this plays out.