I have use Skymiles to upgrade (from PE to J) my CDG - PVG flight begin of December, (the "funny" side is , that upgrade is NOT available with Flying Blue, but have many place in Skymiles).
It is very strange to see place are available for Skymiles flyers, but not for FB flyers on Air France flights... (trying to have upgrade with FB on CDG -> PVG is very low chance, but very easy with Skymiles...)

and receive free upgrade (2) on my middle December flights YUL-> CDG & CDG -> PEK (both from PE to J). and flight from CDG (to PEK & PVG) have the new J seat...