I would think it wouldn't hurt you (other than the obvious of having 1 less real program to rank) if you ranked a program that pulled out of the match. The Match computer algorhythm would just go down to your next program, would it not? I think it's not something to stress about now...most of the programs don't bail out of the match, and those that do you can't really do anything about it.
p.s. I know UT Memphis took 2 spots out of the match (so really only have 2 instead of 4) and U of Louisville usually takes out all but 1, unless they have changed how they do things. California Pacific in San Francisco also removed all their 3 spots from the match and have filled them.
