So you're going to end up with two conferences that matter, and one (maybe two) best-of-the-rest conferences. It's history repeating itself. The split between D1 and DII, the split between FBS and FCS, the split between P5 and G5 and now the P5 is splitting. There's going to be two conferences that are the new P5 and one or two that are the G5 equivalent (by comparison to the Super 2, but still ahead of current G5).

Ultimately, it doesn't make that much (big-picture) difference whether that best-of-the-rest conference is built from the PAC12, from the Big 12, or from the ACC, the resulting membership will be 90% the same. It only matters if you're on the fringes (see Oregon St) and only are included if it's built around your current conference. But honestly, I think both BYU and Utah are solid enough that they'd be in regardless of who is poaching whom.