I’m not a fan of the 12-team playoff. But if that’s what we’re going to do then I think that for several reasons it makes sense to give the byes to conference champions.
First, it places extra emphasis on winning your conference title. Second, it prevents a situation where a team is playing their 15th game against a team that is playing their 13th game and had 4 weeks to rest after game 12. If this format was in place right now and Ohio State was the 4-seed, they could potentially be playing a second round game on 4 weeks rest against a team that had to play a conference championship game and a first-round playoff game since the last time the Buckeyes took the field.
But most importantly, it guarantees that Notre Dame will never get a first-round bye unless and until they join a conference.