I received a request for an informal interview from one of the professors I mentioned in my SOP. He clearly stated that this is not a formal interview and that he's not involved in the PhD admission decisions. To be honest, I’m not sure how to interpret this signal. Could it be that, as an international applicant, they want to talk before making any decision? Or maybe they are unsure about making an offer and want more information first? I’d really appreciate any thoughts or similar experiences.