Wait a min....

Rocksteady gonna present us new Batman villain... Arkham Knight.... and they still dont show us a true identity of ''their'' old created villain named Bookbinder... Created for Batman: Arkham Unhinged, whats somehow part of Arkham City... They don't ''finished'' story with him and give us another one !!!! Arkham Knight !!!!

Or is Arkham Knight - Bookbinder.... actually Councilman Miles Grove ?

I doubt the game will have any tie-in to that comic. Also, as I recall, the Bookbinder's identity was revealed towards the end, it was that suspicious councilman. Yes the story was cut short which kinda sucks, but if you really think about, it wasn't that compelling.