On the 31st of January, a tweet coming from IGN France revealed that WB Games have an announcement to make on the 8th of March.
Warner Brothers Games have a number of studios working for them so it could be anything. However, I believe it to be the reveal of Warner Brothers Montreal’s next Batman game.
The resemblance is uncanny to the reveal of the Batman Arkham games. Furthermore, the iconography in the image looks like the text from the Arkham Origins. 
Plus the “Save the date” phrase just makes me think of the villain Calendar Man. We know that there is a new Batman game because late last year, it was announced that WB Montreal had cancelled their Suicide Squad game to put full focus on Batman.
But we will just have to wait until the 8th to be certain.