Whenever I've been on the GPU waitlist I've noticed that it expires almost exactly 24 hours prior to the flight. Today the waitlist expired about ten minutes prior to the 24 hour mark - and I got an email telling me I'd be rolled over to the gate list. What's odd is that I have an expert flyer alert and I got two emails that at least one seat was released right at the 24 hour mark. Although I know that email time stamps are unreliable, it looks like the waitlist expired then seats were released. When I look at the upgrade list, no one was upgraded to business (or first). This is a flight from PEK to ORD. I'm not bitching about the fact I didn't get upgraded, just find it odd that the waitlist would expire and then seats were released. Anyone have an explanation? Similar experience?