Originally Posted by hillrider

Unless they added new software in the last 6 months or so, there is nothing programmatically that would prevent you from being on both list.

It could be policy, and I can see an outside case where you could end up holding two first class seats (the waitlisted "A" one, and the auto-upgraded "X" one) until the PNR gets cleaned up. The A segment is a waitlisted segment, while the autoupgrade system takes an existing segment and changes it to X, and they theoretically could both clear at about the same time.