Yeah and they're not available. Oregon/Wash are the two biggest brands in the Pac, but Colorado/Arizona are in the tier right below them. If you get Arizona you could be done, looks good on a map, better brands than Houston, and increases your footprint in more populated areas.
At that point, will Oregon and Washington want to wait it out 6 years for a B1G invite when one may never come? ND is the crown jewel of their desire and may want UVA/UNC over you, not to mention Stanford in your own conference. Also, the B1G, like the SEC, has absolutely ZERO need to expand past 16. They control the current narrative and literally any add besides ND waters down their power.
So do you sit it out adding Boise's and SMUs and the like, or do you make the jump to your second-best long-term option, though best short term, and become THE brand in a 16 team conference that gives you games you can win all over the nation?
The fact that the Pac allowed itself to get here is a stunning failure, far worse than the old B12 being unable to work as a team. Instead of working against each other, they destroyed what they had as a team. And now a couple will have an option and are fighting against teammates to survive. Whoever doesn't win out has no option left, but relegation.