Looks like they’re upset that the plan was leaked in an effort to nudge them towards agreeing with it. It does kind of look like that’s what happened. Conversations they wanted to have behind closed doors (P5+1 vs T6) couldn’t and they’re more than a little sore.
Honestly, their tone does not lend confidence that they’re going to get their way.
I think the future of the AAC is still pretty bright (for a G5 conference). It didn’t start out as the dominant G5 conference with the best roster of teams (it was at most tied with the MWC and maybe behind it). But it did have the best TV contract with the most money and most exposure. That in turn helped recruiting and investment. Programs got better over time. Most of those dynamics are still in place.