Not OP, but I applied there last year.
Their process is a little different. You receive an interview, then it's the secondary app. Everyone receives an interview invitation at the same time. So if you don't get an interview invitation, it's safe to assume you've been rejected.
After your interview, a select few get invitations for a secondary app. It seemed like everyone who intervieweed received a secondary tho (at least the people I knew who applied). Then finally after secondaries they make the decision on acceptances and waitlists.
I was surprised I got waitlisted after the interview and secondary app, but I'm not trippin.
Their interview was honestly a joke to me tho. It was a group interview with 9 other applicants and 2 faculty members. Each interviewee gets a turn to answer 2 questions with a 90 second time limit and that's it. No way they were able to thoroughly know the interviewees. Felt like a waste of time.