Not to be stereotyping or anything, but I'd imagine younger interviewers are more likely to call than older interviewers (65+). As Dean Nicholas said at the interview, Columbia was the last med school to switch to AMCAS, and that was because of his doing when he was appointed, with the effort to modernize the admissions process. Calling applicants on cell phones is new and hip, as opposed to mailing the decisions in traditional fashion, so I'm guessing if you interviewed with somebody who is on the older side, they probably won't call. Those I've received calls from this cycle have been young to middle aged (as many med school admissions deans are these days). Just a theory!