It said on the admissions website they would start reviewing your application as soon as you had 2 letters of recommendation in, so I think you would have made the priority deadline! I still have not heard anything from UNC BBSP as well, I know someone mentioned that only one or two programs from BBSP may have sent out invites. Good luck, hopefully we'll all get some good news soon!
I'm pretty sure they said they would send out invites by Dec. 31st. I've heard from other grad programs that Michigan assured them everything would be done before Christmas though...