Any 1 bid league would be silly to keep divisions for football in the potential playoff expansion being discussed.
Say you have the #15 and #25 overall in a single division, if #15 loses the conference championship game, then the conference loses a playoff bid.
Conferences will designate 2-4 “rivalry” teams per team, and those teams will play every year, then rotate through the other 5-11 teams on a multi year basis.