This rumor is in the air, and could be true, but we have to think that the 12nm FinFET of TSMC was made to fight the 12FDX node of GlobalFoundries and 14nm FinFET of UMC.
The main High Performance node of TSMC will remain the 16nm FF++ until 7nm introduction. The 12 nm FinFET is an evolution of the 16FFC (FinFET Compact), so it’s mainly dedicated to Mobile chips.
If NVIDIA will use that node to produce the first iteration of Volta, this means that Volta will fight only in the Server market (HPC) against Intel Xeon Phi (Read our article: "Intel, NVIDIA, AMD: fight!"). So the refresh of Pascal this year could be real, too.