Wrestleview.com’s Josh Boutwell (Viva La Raza! Lucha Weekly) passed this along:

At WWE’s press conference in Mexico City today (hosted by WWE Hall of Famer Jim Ross), they introduced their newest signing MISTICO under his new name “Sin Rostro” (Faceless) but made it very clear that this was the ONE true Mistico. He will be getting a new (probably just altered a bit) mask as he comes into WWE, but they have made it very clear that they want all Mexican and Mexican-American fans to know that he is Mistico. No start date was announced at the press conference.