I checked which aircraft was used on this route since the start of December, the 777s that have been used on this route are only 200s (so do not expect new WT+, WT cabin)
and specifically those:
G-YMMG,G-YMMH,G-YMMI,G-YMMJ ,G-YMMK ,G-YMML, G-YMMN ,G-YMMP. From the above only the G-YMMK has been fitted with New First and is in 12F/48J/32W/127Y configuration.
If you are going for the New First, I would suggest you to call You First for more details in order to be sure and ask if it’s anything on their schedule according to NF.