A & D are not just used for OWE tickets, they are general 'first tier' discounted fares in First and Business respectivly. As an example, my employer has 2 tiers of discounts with BA/CX - the deepest discount booked in D, the next in J.

I class is 'second tier' discount for business class and is normally highly restricted, just like a cheap economy ticket. BA offer these for general sale, and AA from time to time.

Based on the load figures you have, I'd say you have very little chance of an op-upgrade. Unless economy is full, no-one is going to get upgrade when that many seats are available.