It seems interesting... Last year, by the same time (Dec 16, or the first 2 weeks of December), more schools have sent their interviews compared to this year. Although a lot of schools sent on Dec 17/18/19/20.
I applied AFTER the priority deadline and have not heard from UNC (not really surprised).
I guess it may take them some time to send all the interviews... According to their previous stats, they have 1000+ applicants every year.
I did this too!! I was refreshing this page all the time to see if anyone's also anxious about waiting...
Looks like quite a few schools sent their interviews by mid December.