I was able to get a hold of someone and asked about waitlists. They told me they are not done interviewing and cannot confirm how many seats are left or whether they anticipate waitlist movement. It didn't really seem like a letter of intent would make a difference, at least based on the vibe I got from the admissions person. They did mention that the outcomes could be acceptance this cycle, guaranteed acceptance next cycle without an interview, an interview next cycle, or nothing. If I remember correctly, they also said that the admissions committee has not met yet, so they really have no answers. Also, their second deposit is not until May (they might do things a bit diff from other schools) :/