Your chances of getting off a WL increase, sometimes sharply, if you have your high school college counselor advocate for you. In practice that would mean that he can advocate for only one of the choices and that he needs to believe that you are in fact deserving of the advocacy and that you would accept an offer. Having a very strong final semester is a hugh plus in the process. Others on this email thread have speculated that admissions would find updates irritating. I don’t agree. Your counselor will no doubt direct the updates to the regional rep for the college. You may choose to send updates to the colleges that your high school counselor chooses not to do. Go ahead. You have nothing to lose. It’s very hard to imagine that someone in admissions would convert a “yes” to a “no” because they have received an update from you.