My guess is the ACC can read the tea leaves as well as anyone else. They know that they're going to lose their top teams and get poached by the Big 12 and cease to exist.
So their only chance is to be proactive and try to take from the Big 12 now while they can still at least nominally offer some marquee brands.
If I'm the ACC, I'm talking to any and every Big 12 team but particularly focusing on West Virginia, Cincy, UCF (geographic alignment and less loyalty) and Utah (based off their seeming discontent).
And Utah has a history of listening to anyone and everyone and trying to keep options open so I'd guess Utah hasn't outright dismissed them...even if Utah isn't leaning that way, they tend to keep doors open