Just a few reminders:
The B1G already attempted to gut the ACC and failed. Miserably. Sure, they got Maryland, but they almost lost PSU and had to take Rutgers. UNC, UVA, GATech, Duke and the rest are not going anywhere. Louisville replaced Maryland and the only hits taken were academics (and Louisville has been improving them) and lacrosse while improving football and basketball, the two money makers in conference rights.
Texas refuses to look west because of the time zone. They flirted with the issue once, but has since refused to loo west. Texas is NOT married to TTU, if offered the chance, UT would drop them and pick up one of several others. Once TAMU broke UT, UT has no real commitment to the other in-state schools (recall that they dumped UH when the SWAC fell apart because UH was competitive and chose TTU because they were not when moving to the Big 12).
Texas has always avoided the SEC due to academics. Austin has some dignity with academics (football and hoops excepted, as needed) and most SEC schools do not.
Texas has stated they like the ACC. Not clear whether this was a ploy or a tease to the B1G or what; however, UT wants east coast exposure, already has the plains states/central time zone covered.
The ACC landed Syracuse and Pitt with ND as buddy and a deal that if ND football joins a conference, it will be the ACC. See Louisville, above.
OU can probably go to any conference. It has been formally stated that OU and OSU are NOT a state mandated pair (though OU has stated they would try to help OSU). OU has similar academics to UNL, so the B1G cannot pretend academics is an issue. Besides, UNL would love that rivalry to reignite and it would add a balance to the heavier eastern division. OU was part of the Pac's offer to UT, but is not sufficient to bring along three academically weaker brothers (OSU, TTU, KState) as evidenced by their attempt to work a deal to the PAC without UT. Recall that not all of the PAC schools are academic leaders. As noted above, the PAC has little to no interest in religious schools. The SEC would probably let OU bring anyone they want to bring, they can afford to do so and they have no issue with more power teams (they haven't done the math that there can only be one champion yearly, but then, the SEC isn't known for doing math, or English, or history, or science...). The ACC could be interested in OU if part of a deal with UT, yet as a solo outlier, there probably is not enough interest (though Clemson and FSU likely would be interested).*, **
The remainder of the Big 12 is not very attractive, except maybe Kansas: PAC and B1G.
* From OU sources (second and third hand) OU wants out of the Big 12. They hate UT but that is what they have done for over 100 years, being in the same conference is not the issue, falling behind (i.e. playoffs, exposure) the other conferences is the main issue.
**Disclaimer: I wouldn't mind games in Norman. One of my daughters lives 10 minutes from the stadium, no bad seats, hard benches (any good SU fan already knows about these!), fun atmosphere, great tailgating.