I have thought a bit about this, and four points come to mind
1) Boise State's Olympic Sports problem
2) The timing of a move before June 30th to not incur extra exit fee penalties for not meeting the one year notice deadline
3) the American wanting to get out of round-robin waiver for CCG, which expires after the 2021 season, so needing something now
4) the lack of leaks (only the online "prognosticators" are "sources"), which seems incredible if there is more than one school, and more than one conference in talks.
Most likely there is nothing there, just an old rumor dusted off. But if there is and Fluguar's buddy, working probably for the BTN, heard something in the hallway then we have to look at the circumstances where it would be anything.
Boise State had a falling out with the California schools (that includes San Diego State) over philosophy of Covid-19 response; in fact that may have been something of the driver in this, as Boise's coach absolutely wanted the season to get going. I rather doubt things got all patched up that quickly and SDSU suddenly switched tunes, or that they suddenly decided it's OK to dump basketball in a one bid conference (it's not, full stop, period end of discussion).
The lack of leaks, the lack of reporters getting any "hey you might want to watch Boise State" suggests either nothing is going on, or if it is then there must be only one school and one conference involved, keeping contact to a minimum, the number of people in the know to very few.
That gets us back to Boise State's Olympic problem. The American offered Boise State the 12th spot in football only last fall after Boise approached them. Boise State then called around conferences, at least the Big West (no reply, no interest in a rental member it seems), and the WCC (all things on hold, but it's a private, faith based and high AI group of schools, which Boise State is none of). Realizing they had no suitable landing spot for Olympics they gamed out internally how being an all sports members of the American would work and decided while not ideal, it was not as bad as they expected, and something they could work with. So they countered that they'd be willing to come on board in All Sports, but the American balked and it seems to have died there.
If this is truly back on the table, the only conclusion I can come to is the American and ESPN decided it was desirable enough to have Boise State that they would accept them as their outlier in all sports (like West Virginia in the Big 12). SO you have to ask could that work?
Actually yes, and not as funky as you might think. Individual sports only play a league match and otherwise schedule independently (even Tennis -- some conferences do a league round robin schedule, but not the American). So they don't matter, Boise just sends their team to one weekend tournament like everyone else. Basketball is the only men's sport, while women's have basketball, volleyball, softball and soccer. Basketball and Volleyball could be scheduled either as division or shadow division, so that nearly all of Boise's matches would be against Central time zone schools (SMU, Tulsa, Wichita State, Houston, Memphis, Tulane); on the women's side playing the eastern time zone could be as little as hosting 2 or 3 games (one week) and traveling to the east for 2 to 3 games, as the women only play 16 game schedules. Softball could be done in two divisions of 5 (Tulane and Temple don't sponsor), meaning Boise State would be playing Wichita State, Tulsa, Houston and SMU (ECU, Memphis, Cincy, UCF and USF would be the East). Soccer is just a single round robin, which would be 9 games (Wichita State and Tulane don't sponsor), which is sort of like football, can be done on weekends, you only travel to Boise every other year. Really the only difficult scheduling one with heavy travel would be men's basketball with 18 or 20 games. There is going to be some travel.
This is short term. Long term no doubt the American would want to add two more Western schools to balance the league and let Tulane and Memphis shift to the east, and leave the ex-MWC schools to play with the "Big 12 zone" schools in Texas, Oklahoma and Kansas.
That is if there is any truth in this at all, and not a medical marijuana induced day dream.