UNC and UVA are pretty consistently mentioned as primary candidates for both of the P2 conferences. If FSU and Clemson leave and the ACC payout is decreased, convincing two primary targets to stay and make probably 1/3rd the money is a tough sell.
I'll go on record as saying that the articles about expansion are written by people to get clicks, and they don't know what they are talking about (and they don't care because they just want clicks). First, there is a recency bias in about all of them, but I'll leave that subject alone.
People don't understand that UNC and UVA are not the popular "every man" schools in NC and VA. When the FSU AD did a presentation on size of ACC fan bases, his chart showed that NCST and VT have bigger fan bases than their instate cousins. That is something I have known for a long time, but the clowns writing articles don't know that. They are not analogous to TN, Georgie, UK, etc., or even AL or TX. Or Oregon or Washington for that matter.
If expansion is about eyeballs viewing screens, UNC and UVA don't have the leverage that the people mentioning them think they do. The SEC is only interested in more $$, and UVA and UNC won't deliver. The B1G might take them because of academic reputation as much as for footprint expansion, but people have to remember that Oregon and UW are taking a short term financial hit to join the B1G. I'm biased, but GT has as much going for it as UNC and UVA have in terms of B1G admission, yet we are never mentioned.
I don't see the B1G or SEC expanding anytime soon. The FSU and Clemson suits are about getting a settlement that gives them more of the ACC pie in my opinion, and are not about moving conferences. We will see if the ACC blinks.