Two updates:
1) Boston University sent out their Prospective Students' Day invitations that will take place on February 15. As much as I know, they will make decisions from this pool, so if you did not have an interview already and were not invited now, it probably means bad news (Health Services Research program).
2) I contacted the Harvard Health Policy program admin asking if they had already sent out all the interview requests, because it was getting late, and she said that yes they had. So that probably means a rejection. ?