It's actually 99.95, pi, not 99.90+ as you said before.
Anyways, I think the UMAT cut-off won't be below 94th percentile this year, for our year, I know that some people got really high ATARs and managed to get interviews with UMATs around the 91st/92nd percentile (I don't know anyone at all in med with a UMAT below 90th percentile).
My prediction would be 94th percentile to get an interview purely because last year, they offered 3/4s of their interview places on UMAT only and that was 95-96th percetile, so the 1/4 remaining would push it down to around 94th percentile.
But rather than look at the percentile you need to get an interview, I'd say you'd be safer looking at the percentile to be at an advantage. What you don't want to do is be at a disadvantage in any of the three categories, UMAT, ATAR and interview.
Moderator action: removed real name, sorry for the inconvenience