Just submitted an application for my Tax File Number and I'm internally screaming over the fact that I need to do an interview (meanwhile, everyone else in my family didn't have to do an interview -_-).
I just got my tax file number about a week ago and had to go for an "interview" at the post office, it was honestly the most casual thing ever. I booked a time and when I turned up the lady didn't even know I had a booking, she just said "yeah ok I can do that for you now". She asked for my documents, there was an awkward silence while she typed everything up, I had to sign a form and then I left, literally that was it.
So don't stress at all, I don't think "interview" actually means anything