tl;dr: There is no single, magical day when a law school is going to release its waitlist offers.
Even the law schools themselves have no idea — NONE — how many seats are going to be opening up over the summer, or when each seat will open up, and they will keep the waitlist open until the first day of classes.
Yup, you read that right. You might get that call while you're sitting in orientation somewhere else.
My guess is that this summer is going to be a big game of musical chairs, so the admissions season is far from done.
And when you get that call, you'll have to make a decision very quickly. You won't have time to ruminate and stare at your bellybutton, and you won't have time to negotiate financial aid, and you won't be getting an extension. If they have a seat to fill and you get the call, they'll want to fill it with you or move on to the next person on the list, because that will be their priority at that point: filling that seat as quickly as possible.
So be very clear in your own mind which waitlist schools you would say yes to, and in what order of priority. That list and hierarchy might change over the course of the summer, and that's fine. But don't wait until you get a call from one of your waitlist schools to do that analysis, because doing it for the first time under time pressure is not the better way to make an important decision.
If you're not sure whether you would say yes to a school making that call, ask yourself this:
What information do you still need to make that decision that you don't already have?
If you can't think of anything specific, then you're just scared of having to make a decision and you'll need to get over it and stop kicking that can down the road. You've had plenty of time to research schools and talk to students and alums and admissions officers and whoever else might inform your decision. If you haven’t already, start now.
And on a special note: Yes, I heard about the Notre Dame fiasco. I had said it was going to be Waitlist Hunger Games, and boy is it ever. Only you get to decide which schools you really want to attend. I would point out, though, that you should pay attention to how schools treat their applicants, which is highly revealing about their true values. Nuff said.