A while back JAL has converted a few 777-200ERs from W51 into W52 configuration. Basically PY seats were all removed and half of the shell flat seats were removed. So this is configured for high density routes with lower premium demand.
But has anyone been onto flights with this config yet? I couldn't seem to find where they are deploying planes with this config (at least not consistently although there were reports of this being used on BKK flight on certain dates). I checked HNL and YVR, don't seem to be using that now and in winter (although winter schedule hasn't been released yet). Also checked BKK and they don't seem to be deploying them on this route daily either.
My guess would be eventually they will be used on BKK flights as they were planning to upgrade the BKK flights to 777...or maybe for chartered flights too I guess