Update: See comments 1 and 2 below for a possible explanation of what happened here.
About six months ago, I posted about the use of DL SWUs on AF – allowing someone to buy a premium economy (Premium Voyageur) ticket on AF metal and upgrade into business. This was notable because the premium economy prices were much better than DL’s Y/B/M fares, and there was generally “OK” availability in the upgrade bucket. I was successful in getting my ...