I know that official invites have not yet been sent out (to my knowledge, sorry just an undergrad lol- these things aren't always discussed in the open). Here is my best guess (based on current grad students and what I've heard): Most are aiming for January 9th-10th to send official interview invites. Classes begin January 9th, a Wednesday. Clinical faculty also meets on Wednesdays so I imagine the interview invites would be sent either that day or the next.
Sorry that's nothing concrete, but that's all I know