I believe the Creighton AD is full of crap.
Gonzaga isn't going to join a conference where the closest team in over 1500 miles away. They enjoy the institutional fit that the WCC provides.
The Priest isn't bringing in any public schools. No Wichita, no VCU.
If they expand, they'll look at SLU (market), Richmond, Dayton (X might veto). They may consider a couple of others as well, but I'm not going to look into all of the east coast privates and see who's where and are they Catholic or not. I know Catholic isn't a 100% requirement, but pretty sure private is.