Well considering that Izanami and the Priestess are both dead and Izanami being a goddess of death If there is another game this will most likely be true. About "Uzume" you know the myth of Tamahargara in with Susasno ,Tsukiyomi, and Amateratsu I think there is a fourth sankishin unit and that Amane is the user and could possibly be Izanagi given his resemblance to Izanami.