Originally Posted by PHLFlyer

AF oversells the J cabin just as they oversell the Y cabin. Many airlines do this, like it or not. It sounds like people are mixing up different experiences to come up with the blanket policy that AF doesn't honor Skymiles awards. But I'll confirm the following:

1) Z upgrades are gone, based on a decision by Skymiles, not AF.
2) Business seats are all confirmed seats (including awards booked in O by AF or partners).
3) AF policy allows certain passengers the privilege of being "protected" in their class of service (based on terms of a corporate contract, etc.). So, it is possible for Mr Smith from ABC Company with a EUR 30 million annual contract with AF to walk up at the end of check-in and still be assured his J seat, despite someone else having checked in 10 minutes earlier being downgraded. The check-in system "knows" who these passengers are.
4) Keep in mind that a majority of passengers checking in at CDG, despite being 3 hours before departure, are among the last checked-in considering the amount of passengers handled by upline cities (on connection).
5) On many routes the number of protected passengers can make up more than half the J cabin. I have seen cases where 30 people from one contract company take up 40 of the J seats on a single flight.
6) Assigned seats does not assure you will not be downgraded; if there are "protected" passengers without seat assignments they will be re-allocated to accommodate them at the end of check-in if necessary.
7) Downgraded passengers are entitled to downgrade compensation as follows:
---- EUR450 / USD450 transportation voucher + refund of 75% of the fare paid on that sector (paid tkts), or
---- EUR450 / USD450 transportation voucher + refund of the miles between Y + J award on that sector (award tickets), or
---- Rerouting on another carrier in J class (plus applicable denied boarding compensation, normally EUR380/USD380 trans voucher)
For the difference of fare or miles, you must submit the boarding card stub plus your ticket receipt to the issuing party for processing.