This is the PAC one shot to grab legit P5 programs that offer a brand new time zone TV wise.. They won't get another shot.
I agree with this, which is why I think that if the Pac-12 says it is not expanding, it is likely because the B1G/Pac/ACC alliance is going to be pretty substantial. Something like those leagues agreeing to play 2 non-con games a year against each other, and maybe even tying themselves together by bidding out the media rights for those 42 games a year as a separate special package.
Otherwise, it’s pretty short sighted for the Pac-12 to not expand at all. Quite frankly the value of the B12 schools is not going to get higher. If they think they can wait and see how things go, these schools in some sort of G5 middle ground will probably lose TV eyeballs over time. Jumping directly from a league with OU and UT to one with USC and Oregon, with no gap, keeps their value as high as possible.