There are people on the AAC board saying that "the AAC is finished," too, but the truth is that none of the conferences are "finished."
Even if it loses AF, CSU, BSU, & SDSU, the MWC will reload, and some of the upper-to-middle of the pack schools (e.g., Nevada, Utah State, & Fresno) will become the upper echelon FB/BB schools. Meanwhile, BSU and SDSU won't be big fish in a small pond any more, and their teams will struggle if they end up in the Big 12, just like Cincy, UCF, and Houston will in a few years.
Take Utah FB, for example, they were winning 10 games/yr. before joining the PAC-12, but they're a mid-pack team now. Same with WVU, top of the Big East, middle of the Big 12.
NMSU and UTEP and UNT would be sensible additions to replace AF & CSU.
It might be a good idea for the MWC to start talking to Montana & Montana State, etc. about moving up to FBS, which they would probably do if invited.