Virginia isn't getting left out of anything. Oklahoma State and Kansas State also aren't getting left out. Arizona is iffy because they have a highly coveted basketball program (I can agree they get left out if football is the only consideration). I'm also skeptical of Duke, TCU, NC State being left out. SMU is kind of a wild card. I don't think anyone really cares about them, but they have blue blood-level money and have gotten fairly competitive pretty quickly. Houston is the one from your "in" list that I don't really see being a priority to include.
My "in" list for a 20 team conference would be: Notre Dame (mostly a pipe dream), Clemson, Miami, UNC, Colorado, GT, ASU, Arizona, Utah, BYU, WVU, Virginia, VT, TTU, KSU, Kansas, Oklahoma State, TCU, NC State, and Duke.
Out: Baylor, ISU, Houston, UCF, Pitt, SMU, Cuse, Wake, BC, Cal*, Stanford* and Cincy
*I don't see any appeal for Stanford in a world where football is a heavy focus. The only caveat here is that any chance to get Notre Dame to join this conference might be that Stanford is involved. Possibly Cal as well, strictly to have another academic peer involved.