Same thing just happened to me.

I was waitlisted for a flight tonight, and the last thing the RCC told me was that I was 8th on the list for a A319. Stood by for another flight and got on it in coach. I got home and was putting in upgrades for an upcoming flight and noticed that the 2 500 milers were gone. Not only was I never upgraded, but the original flight wound up being cancelled. I have no idea why they were pulled. I did call and they said they'd be redeposited. Perhaps there's been some policy change? I can't think of anything I did that would have caused them to be pulled - I'm positive I never cleared for that cancelled flight.