The point I am trying to make is that we don't know anything about this film. So to complain that a character was announced in a movie that we don't even know the name of seems to be silly.
The addition of WW, Flash, NW, Batgirl, Superboy, Teen Titans, New Gods, Young Justice, Outsiders, JSA, The Wildstorm characters, The Avengers, The characters from the Hobbit, the robots from Pacific Rim….and any other odd assortment of characters you can throw at this movie….would still not make this movie any less a Superman sequel.