According to Reddit user Bandsaw_the_Hedgehog, EB Games informed them that physical copies of Batman: Return to Arkham have been delayed in Australia due to a manufacturing error.
Neither EB Games nor WB Games Australia has made a formal statement regarding the delay. PS4 copies and Xbox One digital copies have not been delayed.
Batman: Return to Arkham was previously delayed on both consoles in July and is now scheduled to release on October 19. EB Games lists the Xbox One copies as being available from November 10.