If I remember correctly, this was discussed at length previously. The result was that for some reason they had problems with Food Trolley’s banking into pax as they passed through the curtain and finally had these seats removed to correct this.

On some of the 777's there is a mini wall similar to front seats in CW that have been installed, but for aircraft that don't have this addition will still have the seat removed, as you have noted in the seat map above.