Idk, at the point of 20 teams, the words 'division' and 'conference' become irrelevant.
The 2 division champs play, so you EARN the right to play a team from the other division.
Yes, in actuality, it'd be 2 conferences, but we'll call it 2 divisions under the single umbrella of a conference.
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Anyway, it's a unique situation in that we COULD go back by moving forward.