The way things are is not the way they will always be. There is no need to label schools or conferences P5 or G5 beyond the duration of the CFP contrct (2026). It is likely IMHO that the Committee will disolve and there will be a scramble to "realign" the entire landscape of major college football. Will ESPN be able to renew the media deal for a playoff-and-bowl-game series? I don't think so.
ESPN has a solid grip on The SEC and The ACC. They will have some competition for the other conferences and the bowl games. That business will be settled prior to 2026.
Thinking outside the box: However unlikely it seems, a scenario like this could develop; B1G, PAC 12, BigXII, and AAC withdraw from the NCAA, form their own governance organ and jointly market their media rights. Not very realistic, but definitely within the realm of possibility. This is a spitball situation. Consider other arrangements that include The Mountain West, The Big East, The Ivy League, etc. The advertising footprint would far exceed the one comprising SEC and ACC. ESPN will not sit on the sidelines and allow these media rights to fall to competitors, but the bidding would be a real spectacle.