The final game in the Batman Arkham series is set to release next week with a fair amount of retail exclusive pre-order DLC. The Community Administrator for all of WB Games has stepped forward to reveal an interesting tidbit of information for the DLC that is on the way.
It turns out the retail exclusive DLC will be available to Season Pass holders and to those that purchase the Premium version of the game. This includes the Harley Quinn and Red Hood Story Packs and any Batmobile or Booster packs that are being offered as pre-order incentives.
The DLC will be available to these individuals sometime around August or September.
The reveal cam through the game's official forums in a post that was detailing Batman: Arkham Knights "release mode." The post from the Community Administer reads as follows:
As I know many people have been asking about the details and content of Season Pass and if or when people will get the content. I hope the following makes things clear:
Throughout the 6 months of additional Batman: Arkham Knight content, Premium and Season Pass owners will receive all in-game content that is offered through various retail pre-order incentives. This includes the Harley Quinn and Red Hood Story Packs, as well as any Batmobile or Booster Pack that was available as early bonuses for pre-order of the game. For those who did not receive the content with their game, these items will become available when their respective exclusivity windows expire in August/September.
The tl;dr version of this is: Premium Edition & Season Pass owners will receive all retail exclusive DLC after their respective early access periods expire.
I hope this helps clear up any confusion, please let me know if I can help answer anything else on the subject.
Batman: Arkham Knight is set to release next week June 23, 2015 on PS4, Xbox One, and PC.