Sure the playoff requires unanimous vote to change the format but Autonomy status clearly does not. No way the majority of the remaining P4 will allow a new conference of G5 merged teams to retain autonomous status..........
"For legislation to be passed through autonomy, the Power Five conferences will select one representative from each of its universities to vote, as well as three student-athlete representatives per conference. Those individuals would cast a total of 80 votes, and an item would then pass in one of two ways. First, if 60 percent (48 votes) of the vote and a simple majority of schools from three of the five conferences support the item, it would pass. The item could also pass if a simple majority of all votes (at least 41) and simple majority of the schools in four of the five conferences support the measure."