Concerning my corrections, I did not see, in the two hours of cinematic of the game, any proof thet this Diana was effectively a "rebound girl"; it's maybe what Deathstroke believe (or he knows it's wrong and it was to taunt her, and it's maybe what Diana would like everyone to believe. )
But: she's a right hand, like Hal Jordan, but no proof she's anything more despite she whishes to. In particular, there's the scene where she enter in a striperiffic dress, and with the speech: "I do not mean to replace Lois, but..." . Injustice! Superman absolutely not notice her, contrary to Hal Jordan who have to point it to him. Clearly, this is the kind of story where Superman is an inconsolable widow, and do not have a "rebound girl" because he's not in the mood; his only mood is to get revenge ont the world and only have interest in Lois as the ending proves it. Learning about the other dimension and the existence of a living Lois, he decide immediately to kill his double and get her in said dimension.