The ACC's grant of rights by all of the members, including the incoming members, at what I've heard but can't confirm is at all levels, might have stopped the carousel. It makes any ACC school much less valuable for media to any other conferences. And since the Big XII has set a level of $26 million a year for any incoming schools to be worth dividing the pie any more they are probably done.
I haven't seen if the ACC's team has any allowance for increased payouts by adding schools to their conference. I doubt it does because 1. they don't want to encourage movement and 2. if the SEC didn't get any more for A&M and MIzzu I don't see anyone the ACC could get being worth more. If the ACC isn't expanding, then the AAC is safe which means CUSA is probably safe which means the Sun Belt is probably safe.
Here's the article.