Conference realignment is only about eyeballs.. TCU was a desperate take just like Houston would be. They are both fine athletically, but they don't add enough to the TV money. That's why Cincinnati was considered a better take than Houston. I guess people from outside of Texas don't realize that A&M and Texas dominate the tv viewing in the state, with Tech a distant 3rd. A&M, Missouri, Colorado and Nebraska were big losses as far as tv revenue goes. BYU and Cincy would have made sense if you could get them but that's it. Its obvious now they would only have been able to get Cinci. You don't just add Houston because you can't get someone else and they weren't going to add an odd number. I think a lot of people just think of BYU as some oddball school in the mountains, but they are the Mormon Notre Dame, with alumni all over the world and their own network. They would have been a great get for any conference, except you have to deal with them religiously which is a big no go for many major universities because of some of the official Mormon Church stances
Texas and OU are doing fine financially and both are waiting for the best situation for themselves, which may be when the Big XII tv contract is up as well as the current CFP contract. There's no need to panic right now for either.
If you're wondering why Texas hasn't played Houston in a while, it goes back to the early 2000s. Texas and Houston agreed to a home and home for 4 years. The agreement was to play at DKR the first year, then the Astrodome in its final year to have a larger crowd then back to DKR, then to NRG. Houston instead wanted to play at Robertson Stadium, which held like 25000 at the time, which broke the contract for the last game. For that game, they erected about 10,000 temp stands, but a large section that was mostly Texas fans was condemned, angering Texas officials. They haven't played since.