Yes, thank you. Who here thinks the OP, who has 6 posts in ~2-3 months on FT, knows the meaning of GUC, OpUP, or FCM? (I'm surprised nobody mentioned MUA).
If you want to help, then help.

Shorter answer for the original poster - Upgrades to DeltaOne are essentially off the table unless you are willing to pay for them, either with Global Upgrade Certificates (GUC), Mileage Upgrade Awards (MUA), or a "First Class Management" (FCM) paid offer online or at check-in. Additionally, sometimes the airline will have to upgrade people if coach is oversold and there is space in business class, these are "Operational Upgrades" (OpUps). Never expect one of these. With FCM, the number of OpUps may have decreased as they've figured they can get someone to pay, say, $500-800 for what they'd otherwise have to give away for free.