So if I didn't have the 13-18 minute wait for a call back, I could have conceivably jumped the queue if there were previously waitlisted mileage upgraders?
There were reports here on FT confirming that!
When I received an EF alert, I Tweeted AA if they could HOLD that C space for me due to EXP desk phone would be able to return call more than 60 minutes (during bad weather). AA Tweet team did and I got UG'd. You have to give them Record Locator of course.