For everyone freaking out about "interviewing for the waitlist..."
Three schools I got interviews at (DO) explicitly stated in emails that interviews later in the cycle would be interviews for the waitlist. I didn't want to deal with the drama and promptly withdrew from those interviews, mostly because I had other acceptances I liked better.
Point being, it seems to me that it is neither unusual or uncommon for schools to interview solely for the waitlist. It makes even more sense if, like Nova, they're sending out so few initial acceptances. What were they supposed to do - only accept 50 people, reject everyone else... and then have a class of only 20 people if 30 withdraw?
There has to be a waitlist, and with a new school, it needs to be decently long. Besides, if you interview amazingly well, you could bump yourself to #1 on the waitlist, which is a fantastic spot to be in. Just because you're interviewing for the waitlist doesn't mean you won't promptly get off the waitlist the second movement starts if you're a strong candidate. I don't see what all the angst is about.