Your system came with that additional copper sheet and it sits between the CPU and the copper heat plate?Which make sense, the later model (mine is from December) have an extra copper plate in between from the factory. Therefore you need less cooling paste which improves the heat conduction.
Here I'm upgrading the cooling paste to a better one. Coolingpaste is in between the copper and on the cpu side.
View attachment 26808
That's neat. I'm glad they're working on improving the thermals, even if it is in a weird way.