Rocksteady's Batman: Arkham series has been deservedly praised for elevating the Caped Crusader's reputation in gaming, and while Arkham Knight's key plot revelation was far from surprising, it was a crucial part of Bruce Wayne's character arc. The game was well-received as a suitably explosive finale to the series, even if the twist didn't have the expected impact, proving to be a key piece of Batman lore that was a long time coming.
Source:https://www.cbr.com/arkham-knights-twist-importance-to-batman-arc/