Judging from my personal experience last month, I'd say something IS going on with the AF/DL relationship. On an outbound ATL-CDG flight, the AF gate agent tried to downgrade my wife who had an O ticket (90,000 miles redemption), and not a Z ticket (upgrade), claiming AF no longer honored DL award seats. In retrospect, I think she was confusing the new rule no longer allowing Z upgrades. In any event, she relented and let my wife take her seat in coach.

On the return flight (CDG-ATL) a week later, AF downgraded both my wife (on an O ticket) and me (on an I ticket). They did so despite the fact that we had assigned seats (confirmed 3 times during the week prior to the flight), despite the fact we arrived at CDG almost 3 hours prior to departure, and despite my protests about my Elite-Plus status. The lounge attendant who advised us of the downgrade even made a snide remark about how they (AF) wish they didn't have to deal with Delta passengers at all.