For what it is worth, I think Texas is a bit nostalgic. I said years ago that the Big XII really screwed up in letting Colorado walk, and not expanding with Utah and another mountain state/southwestern school (pick Nevada, New Mexico...). WVU was an error. The loss of Missouri and Nebraska pushed the geography of the league further southwest. They could have boxed in the Pac 12, and been in a good position to poach an Arizona school.
Unfortunately, they utterly screwed that up, and have now lost A&M as well. I will say it now...Texas will not get to play in a geographically aligned conference at any time in the foreseeable future. It's over, they blew it, and it's largely their own fault.
The ACC doesn't have this public in-fighting. They have a pretty cohesive geography and several like minded schools. They are watching, can see where the Big 12 screwed up (and they screwed up with Maryland) and I think they will succeed in shoring up the league in some fashion. The odds of those schools defecting to the Big 12 is very low.