Some news has broke today that the ACC's 15 members have agreed to an exclusive grant of media rights. In short, they've agreed to allow the ACC and the ACC alone collect money from media outlets that wish to broadcast their games (which the league office will then distribute evenly to all of the schools after it takes its cut). The agreement extends through the 2026-27 athletic year.
Why do we care? Because basically it ends any shot at the SEC adding any more schools unless something totally unforeseen happens. A grant of rights is what has saved the Big 12 from splitting apart after its 2010 and 2011 defections, and now all of the ACC is locked into one as well. All speculation on further SEC expansion has centered on ACC teams such as Virginia Tech and NC State. If the conference decided to add them before the 2027-28 athletic year, all media money generated for those schools would now flow to the ACC instead of the SEC. In other words, there's no point to anyone raiding the ACC for about 14 years.
It's probably a more pressing issue for the Big Ten, which has been rumored to be looking at ACC schools on top of Maryland for a while now. Plus if the Big 12 ever really was interested in adding FSU and Clemson, it won't be anymore. I never got the feeling like anyone really thought the SEC would be proactive in expanding to 16 anyway; its expansion to 14, after all, was largely a result of opportunities provided by others acting.
So if the SEC did want to go to 16 members before 15 years have passed, its options consist of anyone outside the four other major conferences. In other words, it has no expansion options. Get comfy with the 14-team model, because it's not going to be changing for a while.