And yet we have Conference USA, which consists of schools so unwanted by the others for various reasons (poor locations like New Mexico State and UTEP, absolutely no effort to make athletics relevant like Florida International or Middle Tennessee State, or are just extremely toxic a brand like Liberty or Louisiana Tech) that you're only joining because it's not the MAC.
So the current pipeline of schools going from FCS to FBS will be them joining a lesser conference to pad out the stats and hoping they get good enough for an American Athletic to poach them. But as I've said in other threads, if you're west of the Mississippi, that's a problem due to the travel. And these super conferences mean less buy games available for scheduling.
I THINK you're referring to Idaho's drop to FCS with this?
Idaho was shut out of the FBS conference that had Boise State, Utah St, Nevada-Reno, Wyoming, Colorado State and Air Force nearby.... but there was an FCS conference with Eastern Washington, Portland State, Idaho State, Montana, Montana State, Weber State and Northern Colorado right there.... which was their PRIMARY CONFERENCE for all other sports already.
C-USA is the "entry point" for FCS schools moving up -- that used to the be the Sun Belt, but the SBC leapfrogged them (mainly because C-USA replenished their conference with "markets" that had bad teams in them, so no one watched anyway, while the Sun Belt was "stuck" with small college towns with directional state schools in good recruiting areas that just played good football (like App State and Coastal Carolina and others).
Before THAT, the "entry point" conferences for FBS was the Big West... which is how Idaho went FBS to begin with. The Big West needed programs with Long Beach, Fullerton and Pacific dropping football and losing members like Fresno State, UNLV and San Jose State to the WAC. Idaho was a top I-AA team so they tried to make the jump.
It made sense for Idaho to go BACK to FCS because with 11,000 students they were one of the smallest FBS schools, and their stadium seats 16,000, also among the smallest. The NCAA's attendance rules for FBS put them in serious jeopardy of being forcibly sent down anyway.
The reason Idaho is the "First school to VOLUNTARILY drop to FCS" is because all the others were FORCED down by NCAA rules (most notably the MVC and nearly the MAC).