If you are interested in the school, I think you should go. You will not just be interviewing for the waitlist. Many applicants that they interviewed earlier in the season, they have put on "hold" to be reviewed again after they finish interviewing ALL the candidates they are interested in. Thus, it would appear to me that you have just as good of a chance of being out-right accepted as someone who interviewed in the fall or winter and has been placed in the hold category.