According to the Dude over the past month the Big XII brought back its expansion committee to look at additional schools because there is a belief that the new Division 4 and the Playoffs are going to really emphasize Conference Champions from a Championship Game. The Big XII is at 10, and can't play a Conference Championship Game unless they add 2 members.
According to the Dude, the Big XII expansion committee has determined that adding 2 members will cost the current members about $4 million per year each in television revenue. ESPN and Fox have apparently told them that there will be no more money for more members. He's basically saying that they have looked and Cincinnati, USF, UCF, UConn, and Fresno State are duds in the way the Big XII Television is set up. Expanding into new markets might help a conference like the SEC or Big Ten that has a cable network and is looking for subscribers, but if the Big XII adds teams they don't need subscribers, they need ratings which are different entirely. The schools out there and available won't drive ratings.
So the Big XII will not expand at this time, and the Dude concedes that this will put the Big XII in position in 2025 to lose more members. At least he is now discussing the league that WVU is actually in rather than the ACC or Big Ten. Here's his article. I know it's the Dude, who is usually incorrect, but it's about what he thinks that the Big XII is doing.