I think you might be confusing the UQ-O and UQ traditional programs. The Ochsner program has had interviews for a while now. The UQ traditional program recently added interviews as a requirement. Ochsner made them add a interview after the first couple of classes made it to New Orleans and there were some students that personality wise were not fit for medicine. This is the first year they are doing MMI though. In previous years, the interview was talking for 6 minutes each for several questions without any real interaction from the interviewers. If you passed, your packet was sent to Australia to be reviewed. If you failed then you received an email informing you, your application would not be to sent to Australia.
Also, during my visit to New Orleans, the Dean mentioned they are trying to have a smaller class size than in previous years.
Sorry to hear you got rejected. Good news is that you can always reapply. Based on the GPA/MCAT of others that were accepted, it seems your MMI was what held you back. Thats honestly one of the easiest things to approve on. Best of luck.