I have an idea. Instead of making everyone wait, there is another option.
At the end of the interview day, the admission committee should take a few hours to make a decision. Then after that, they should call of the students in, at around 8:00 P.M.
And then the admissions committee divides the room into three groups: the rejections, the wait-lists, and the acceptances. The faculty visits each of these rooms and tells everyone the news on the same day!! How about that?

Just like American Idol!
Or about like the international piano competitions? They should have the committee come out (make a long speech about how difficult the decision is!), and then announce the rejections first, the waitlists next, and the remaining people not announced are the ones that are accepted!! And everyone sits in a large auditorium as they do this!! A lot of people, of course, are crushed after the announcement (and I have been crushed too several times!), but that is the way it is, I guess.