I have seen your argument work in basketball (a lot sadly) but I haven't seen it for BYU football.
Utah State played 2 P5 schools last year (and I believe Wake Forest is coming back to Logan). SDSU got Stanford at home last year (and played ASU as well). Fresno played Washington & Alabama.
I've seen to many great teams come to Provo to believe that will stop just because we joined the AAC. I would expect that our SOS would actually improve and our program over time would recover as well. I believe the current indy path is headed to the death of BYU sports - just watch to see how many people show to watch BYU-USU after BYU starts 1-4 or even 2-3 this fall.