The change in AE upgrading policy that was made about two years ago related to AE tickets booked in business class for some but not all segments. Any AC segments in economy could be upgraded on the day of flight subject to available space on the flight. This is no longer possible. As noted, AE tickets have never been upgradeable with certs. And though not confirmed by first-hand experience, some have recently posted that when they checked in, even on an award ticket, they were offered a Last Minute Upgrade for cash. This is not universal, nor as I said, verified by an FTer I know and would trust. (Check the Last Minute Upgrade thread.)