I dont think we really "know" that, not to mention the GP104 cluster may not be the exactly the same as GP100 cluster. I mean, it can have the same 64 FP32 cores, but not those additional 32 FP64 units (but say only 8 instead per cluster)...that should save loads of die space, right?
Even 8 FP64 units per SM would be overkill for a '4'-series chip. GM204 had a 1/32 ratio - that would equate to a mere 2 FP64 units per SM if the modules still have 64 standard CUDA cores as they do on GP100.