It could be a mistake or a hoax, or it could mean that NVIDIA is preparing a faster version of the GeForce GTX 1070 to turn up the heat on AMD. At the moment, there's a relatively large gap in performance between the GeForce GTX 1070 and the GeForce GTX 1080, so NVIDIA could fit a GTX 1070 Ti in there to complicate things for AMD's Radeon RX Vega 56:
Why would NVIDIA make GTX 1070 Ti? Well, it’s quite obvious that Vega 56 is faster in this price segment (at least when official price is considered). NVIDIA could either lower the price of GTX 1080 or bring a new part.If there's any truth to this, these cards could launch relatively soon as the photo below implies custom-design cards are already circulating in the wild.
Via VideoCardz