My guess is there is no "reasoning" and that is it more the result of 1) having received a pile of last minute apps that they feel honor bound to review before making final decisions, and 2) having jobs that include many duties beyond being a TD, so that clinic crises, budget deadlines, etc., can make them work on very tight, multiple timelines. For the majority of TDs, that role is only part of their job.
I matched to a VA site, and I had zero problems transitioning back to AMCs for fellowship and employment. I'd rank the VA & AMC sites by fit and not the type of setting. If you *only* have VA experience, it might be helpful to have AMC experience, but I don't think that is a dealbreaker. The same holds true if you *only* have AMC experience. Solid clinicians/researchers get offers for both settings....I guess I just got lucky. 😉
The general advice to training directors is to only let not-to-be ranked candidates know if the TD wants to deliver the news and it is well in advance of the deadline. Close to the deadline it is anxiety-inducing and, as you note, better to just let the ranking and matching process do its work and for everyone to rank for what they want. The algorithm handles it without changing your rank order of your options. I also think directors are flirting with rules violations if they make calls to folks individually about ranking them as how your handle the verbal exchanges can be so vulnerable to mis-interpretation. A standard email to all candidates conveying they are among the ranked is clearer and cleaner, but even that should not be interpreted, by its presence or absence, as a signal or sign. It is a tough process all around for sure.
