I think the relevant contract says 75% of the membership must vote to dissolve, so, in a 10-school league (versus the original 12), I think one can safely assume that 8 votes is the requirement today for dissolution.
It's been several years since I read the GOR and league contracts, but the information posted above by ButtFumble comports with my recollection, FWIW.
I vividly remember strong tampering provisions in the GOR, especially as same apply to member schools.
Still, as June 2025 approaches, the tampering provisions will become increasingly irrelevant.
Why? Waiver.
If the GOR does not become renegotiated in the 2023 to early 2025 timeframe, then there will be significant discussion about "what's the holdup?".
If the B12 renegotiates early, then Texas and Oklahoma almost certainly will have elected to stay in the B12 and try to make it reasonably financially competitive with the B1G and the SEC.
If B12 GOR negotiations drag into 2024, then into 2025, I feel reasonably certain that waiver will arise.
The tampering provisions will eventually become moot because it will be the bottom 8 schools - not necessarily Texas or Oklahoma - that will waive the tampering clause.
If there's no GOR renegotiation, it will be the TCUs, the ISUs, and this group of school admins that will be sweating it, publicly speculating about it, and thereby waiving the tampering clause, not Texas or Oklahoma.
We will know what's going on, no doubt, one way or another, in the next few years.
We will also have the advantage of analyzing the B1G contract in 2023 and the PAC contract in 2024, which may contain interesting provisions about escalators, in the case of the B1G, and escape clauses, in the case of the PAC. So, there will external contextual information, too.