The cool but short Batman Arkham VR game released for PlayStation VR last year is now out for Oculus Rift and the Vive. This is a canonical part of Arkham lore, but saying just how it fits in would be spoilers. Read: Our review | A fun easter egg for it in Arkham Knight.
Again, without spoiling anything, it’s not canonical in the Arkham universe. There are people who are dead in the VR game (which is supposed to take place between Arkham City and Arkham Knight) that are alive in Arkham Knight. If the major events that had happened in VR had occurred in canon, they would have been totally continuity breaking in Arkham Knight