There's a bigger set of issues to moving up... especially if certain pieces of NCAA legislation are enacted.
(1) The target does not abide.
The Mountain West didn't quite give up the store to get Boise State back in the fold, but BSU certainly got all the power.
All of it. The TV contract provision is an interesting deal to say the least.
Boise State wants to fight for RPI, basically. It's bad enough that not everyone in the Mountain West will be up to that standard... though they and everyone else seemed to bail on the Big East after they added Tulane. They don't want any FCS schools that are just as likely to drag down the strength of schedule in football. If the MWC does expand, they want Houston and SMU. Boise says so.
(2) A not-so-quiet NFL lawsuit presents a problem.
There was a situation where the NFL was caught with helmets off last month (or two months ago) when the players presented a document that shows the NFL DID have concerns about concussions.
If the NFL loses that lawsuit, they may end up paying out a lot of money (by our standards), but they can probably handle that. Insurance for smaller school football; that'll be a problem. The high schools, I shudder to think.
If this doesn't disrupt the short term prospects for Portland State, then the long view certainly raises some broader issues. Of course, nobody should be surprised if the NFL can create a deflection, but the damage may already be done.
(3) The stipend.
A couple thousand dollars per year to athletes for living expenses? It's on the NCAA docket.
Even Boise State is scared of this legislation. Chances are this would have to apply to all athletes, not just football players. That means your current Big 5 (and dropping) "BCS" schools with $20 million per year in TV revenue may have problems, but not too many. Everyone else may have to form their own division, or drop.
(1) is most important. (2) and (3) depend on future events. None auger well.