No, the highest fare bucket I've ever bought was Economy Saver N, just about all other tickets were from the lowest fare buckets. The fare class seems to make no difference. The back to back SOF-DOH-BKK op up was a N class, but few of my tickets have been in that bucket. I was Plat for three years, gold for three either side. It all seems to be down to status, though that that hasn't always been the case, as I experienced during my early QR flying days when I had two op-ups from Doha, old airport, based on appearance alone.

There's a certain amount of luck when it comes to op-ups as a moderately loaded flight from Doha can suddenly become well oversubscribed if an inward service is heavily delayed, causing passengers to miss their booked connection, with the resultant need to accommodate them on the next available flight.