Should I contact a potential PhD supervisor who strongly encouraged me to apply after not having heard from my application? I have applied to an interdisciplinary program in a very top US university. My undergrad is in one of the fields involved. Back in November, I contacted a potential PhD supervisor (sending him my CV). We had a chat over Zoom, and he told me that I &quot;will get offers&quot;. He told me has spoken about me to a Prof at my current institution who knows me, and based on my background, we started discussion potential projects and co-supervisors. He encouraged me to chat with one of his current grad students, whose undergrad is on the same field as mine. When I chatted with the PhD student, he was really trying to &quot;sell&quot; me the university. He told me that it was very likely that I will get invited for an interview and get offers. It's now February and:

I haven't heard anything from the program
In gradcafe, at least 2 students mentioned that they were invited for interviews in December
I asked the PhD student if he knows anything, he said he doesn't.

Should I contact the potential supervisor, in case my application was overlooked and he can still do something? (He is not on the main committee of the program, though.) On the other hand, I am afraid of looking impatient or unpolite, and ruining my remaining chances of getting in.
(Note: I am an international student, studying outside the US. Is there any chance that international applications are processed later, or don't get interviews because of timezones?)
From my experiences in an engineering program at a public university, I've heard that domestic applicants are processed first. I don't think it would hurt to follow up with the potential supervisor. I agree with astronat above about sending a  polite email to follow up with the potential Ph.D. supervisor. You could also ask this professor when you can expect to hear back from the university.