I do not know whether this will offer any encouragement for other students who have been waitlisted this year for undergraduate programs.
However, my daughter was just accepted off a waitlist for a PhD position. She got a “are you still interested” email last week, replied quickly (bullet item #5 from the list above is important), and just got her acceptance today. This is for a very good program for what she wants to study (I won’t say which one given the small size of the program and the second word in this web site’s name).
We are still a bit in shock, but excited.