They don't need UNLV to get Vegas.
This is something I think people forget. No conference needs UNLV to own the Vegas market. If UNLV has sustained success, then gets invited to a better spot, it comes with new fans. But as is, 3 of the P4 can claim sovereignty over Las Vegas. The Big 10 because of the two LA schools. The Big 12 because of the Arizona schools and the Utah schools, therefore influence by relevance. The SEC owns any major city where they put two of its teams.
Just to divert pack to the concept of a Pac 8... I think I quite like it for (or even a Pac 9, since we are already beyond full regionality due to there not being enough teams in this part of the US, and also since divisions aren't require for conference title game)... Full football round robin, equal and complete scheduling... which you could do with 10, but does it really matter? Pac 8-10 it's doable. Ya know what? Sign me up.
WSU and OSU
BSU and Fresno
UNLV and SDSU
CSU and USU
Then determine with TV partner guidance whether or not it's worth bringing in Wyoming or AFA or 2-4 Texas/Louisiana/elsewhere (Really only UTSA, Tulane, Memphis... maybe a Texas State if you get UTSA... San Marcos and San Antonio are an hour apart, I think that's huge to give them a natural regional rival... they have never shared a conference, at least not in D1A.... Texas State was decent last year, but has been mostly bad in recent history. Like 2-4 wins. They are probably too much dead weight currently.)
...stream of consciousness typing.... Anyway, uhhh... UNLV not needed for Vegas market, and give the Pac 8 a thought...