wild guess is that it takes place prior to ME3, wouldn't be shocked at all if Shepard wasn't involved either and that these new characters mentioned were the ones used.
@ecs33 Blizz could also recommend that players use a usb keyboard and mouse to play the game, and make the controls like they were for D1 on PS1. People would go for the keyboard/mouse combo for sure.
damion_silverbr's comments