then what is WVU's incentive to remain in a conference where the members are Iowa State, Kansas State, Oklahoma State, TCU, SMU, Houston, Texas Tech, UTEP, and 3 other schools from the Midwest and/or Mountain regions?

Also, you have to consider the possibility that the Big XII or Big XII 2.0 may decide to kick WVU out of the conference just like the Big East did with Temple. If the conference wants to expand and keeping WVU would result in the conference having an odd number of members, then it may chose to kick WVU out instead of adding another member to bring the total membership to an even number.

Mathematically it is impossible for a conference with 13 or 15 members to play a round robin division schedule and every member play the same number of conference games in order for the Big XII to continue holding a conference championship game. The MAC never did it when it had 13 football members. The MAC quickly discovered that teams could either play a round robin division schedule, but not the same number of conference games or everyone plays the same number of conference, but some teams won't play a round robin division schedule.