I think the only way Pac 12 school leave for the Big 12 this year is if Kliavkoff is truly unable to get a deal on the table. If he promised $400M a year and is currently getting offered below $300M that's pretty bad, but it's hard to imagine anyone leaving the conference over it right now when the difference in payout is going to be maybe $5M annually either way.
The deal-breaker might be Oregon and Washington insisting on unequal post-season sharing and the Arizona school refusing those terms. I don't see anyone leaving over the streaming issue, though if that doesn't work out very well it will absolutely create resentment moving forward. Even if no one is excited about SMU and SDSU, Utah or Arizona isn't going to join a conference with UCF in it just to avoid SMU. The uneven revenue is the only thing big enough to make this all unravel for the Pac right now.
That said, there are many reason to think that the Arizona schools, Utah, and Colorado will make this move by 2030:
1. Worse money and TV visibility under the Pac's (yet unfinished) media deal.
2. Unequal post-season revenue sharing.
3. Oregon and Washington leaving for the Big Ten.
4. SMU and SDSU not improving the conference.
Even the Pac homer John Wilner recently wrote that he thinks the landscape after 20230 will be three major conferences, comprising an expanded Big Ten, SEC, and Big 12. I think that's right. We can be patient, and evidence thus far suggests that our conference has better leadership. Kliavkoff totally screwed up the Pac's opportunity to poach the Big 12 in 2021 and the media rights situation in 2022-23. That's only going to fester with time. Unequal revenue sharing always increases tension, and if SDSU and/or SMU bring sufficient value to offset that they'd have been invited a long time ago.