I just can't see Cal keeping UCLA from moving. But I believe the B1G is trying to kill the Pac slowly, so I expect that Oregon, Washington, Stanford, and Cal are also gonna go to the B1G in the years ahead, too, as they conquer the West to keep up/ahead of the SEC.
If the model becomes two major conferences, 24 teams each, the SEC will wait out the ACC to add in Clemson, Florida State, Miami, UVa, Va Tech, UNC, NC State, and Duke to get to 24 teams. Then, the B1G will add in the those Pac teams that I mentioned, as well as AAU brands in Kansas, Colorado, Utah, and Arizona to get to 24 teams. ND will stay independent.
The remaining leftovers in the Big 12, ACC, and Pac will be the third level, still considered FBS, but with much lower payouts.