For all of those waiting, I totally know how much it sucks. To provide more transparency, here's some information that will hopefully help:
The bad news:
All March interview slots have been taken.
The good news:
There's a ton of interview slots in April
What it means for R2 applicants?
I've called Stern and they said that since they do rolling admissions, getting interviewed in April after the R2 decision date doesn't mean getting pushed to R3 (she said there is no concept of "rounds" for Stern). For those who have not heard back before 4/1, you will either get a waitlist or ding. Waitlisted candidates will have a chance to get invited to an interview, but this doesn't mean you are in R3. Again, she said there's no concept of rounds for admitting people. They just admit on a rolling basis all the way till before class starts.