Not always. The YONEPASS fare basis is not always valid. Last year I bought a $2000.00 Y ticket BOS-LAX. Y class not YONEPASS and at the time A & D class were available (I remember since I would not ticket the flight at that cost if I could not get the instant Upgrade). I did get F/C, but due only to my Platinum Status.

Maybe our good friend CO757 could help? CO757, If your out there and have a few minutes, could you ask one of your coworkers our question about waitlisting priority?