I know New Mexico will throw a hissy fit about including NMSt but when they decided to stay in the lesser western league they lost all ability to think they're better than anyone. The MWC needs more western teams and NMSt is sitting right there in the footprint. And the hope would be that the rivalries among UNM, UTEP & NMSt would help elevate each of those programs. Each has had significant historical basketball success, maybe competing more often will elevate them all in football.
Texas State has recommitted to the Sun Belt, but if the MWC proves it is on a different level Texas State will be interested. The MWC could use a Texas presence both for recruiting & central time TV windows and it helps that UNM & UTEP are already in the neighborhood so TSU wouldn't be on too much of an island.