It sounds strange I must say. I have never heard of an upgrade list, also I have never seen more than 4 seats ever in J. I use Expert Flyer to check and it has always been useful.

You can also upgrade at the airport. As I understand it, they will upgrade you if there are any seats at all available. I've done that on a IST-PVG flight. It was all done in the TK lounge at IST for me.