Sure enough, ISU is not considered "MEGA", and is a leftover:
Teams Left Out: Cincinnati, Baylor, Boise State, Texas Tech, Louisville, Iowa State, Fresno State, Houston, Memphis, San Diego State and Wyoming. One thing is for sure, Cincinnati, Louisville and Texas Tech would be a great addition for any conference to grab.
There's 11 schools right off the bat. Add another leftover (Colorado State? Air Force? Memphis?) and you have a league ISU can compete in.
Since ESPN drives the narrative, and has a financial interest in the MEGA system, look for it to happen.