I’m not sure about “instant denial”, as you said they would usually put someone in AP/refused before making a decision. However, one meeting (especially if it was short) can be problematic for a “tough” consulate and I’d categorize Tunisia as such.
You mention it is not possible to meet before/at the time of the interview. Is your interview scheduled very soon (as in the next few days) already?
I’d do by best to meet at least once before the interview. I was asked at my interview when was the last time I saw my fiancé and back then the process didn’t take as long as it does now, plus it was in the midst of COVID border shutdowns, but there was definitely an expectation from the CO that we’d see each other again after filing the petition (which we did). In your case CO might have questions as to why you went so long without seeing each other.
It all boils down to what your risk tolerance is and personal decision. If you’re okay with taking the risk and going in with what you have at the moment then that is your decision.