The most likely realignment scenario involves putting the historic rivals in different divisions, then having them play in the middle of the regular season rather than at the end. That way, if they meet in the championship game, it won't feel as much like a rematch.
Never mind that few championship games are as memorable as even the clunkers Michigan and Ohio State have played over the years. When pressed, most coaches would concede they view championship games as necessary evils; they're the price a team pays so that its conference keeps a seat at the table for the postseason galas.
But no one ever looked at Michigan-Ohio State that way. The lore that grew up around the game was testimony to that. Play it twice a year, even if the second time is for the league championship, and plenty of the air leaks out of both