I got a call last week as well - my interests are in AI/ML. Top liberal arts school (when did we get the liberal arts label stripped?!), adequate GPA, adequate GRE, one publication for a big conference accepted and one submitted, and what I suspect must've been damn good LORs given my GPA.
My suspicion is that most AI folks have been contacted, and as turkey mentioned, POI's appear to be operating on their own schedule. Hope things go well for you!