Award & Upgrade Availability (using DL SM SWUs) on
AF uses the same exact Booking Class:
http://Help.KVSTool.com/#Classes
Therefore, it is technically impossible for Awards to be "limited", while the Upgrades are "still possible".
"Technically" speaking you may be right, but realistically, I talked to a total of four DL agents at the SkyTeam upgrade desk, who all said they were unable to see any availability for the O bucket (and I confirmed with each of them they were looking at the O bucket).
So, it doesn't work.