Guaranteed interview from sub-I?

Hi!

I heard from an upperclassman that usually, you don’t need to signal a program if you did your sub-I there because most of the times, you’re guaranteed an interview? Not sure how true that is but I’m doing a two week sub-I that trickles into post-ERAs submission and was wondering if I should be giving them a gold (assuming I had a good time and do like the program).

Is there a good way to ask PD or anyone from admin if I would be getting an interview?

TIA