Hamish Linklater was reportedly "obsessed" with Batman: The Animated Series (1992) and Kevin Conroy who starred in as Batman. "And I think - even though when I was making my audition tape, I certainly wasn't trying to copy him - but those vibrations were [there], that sound was in my head, and that was, I think, probably what I was pursuing."
Jamie Chung initially portrayed Harley Quinn as a "terrible version" of the late Arleen Sorkin's original portrayal in Batman: The Animated Series (1992) - before she was told not to do that and to "try something else."
The 2014 animated short titled "Batman: Strange Days", created almost a decade before the show, served as a pilot of sorts and unintentionally previewed the show to come.
The Gentleman Ghost is originally a Hawkman villain with no connections with Batman.
After the cancellation of completely finished movie "Batgirl (2022)" with Michael Keaton returning as Batman, Warner Bros. Discovery continued with cancellations of DC properties. The decision not to release "Batman: Caped Crusader" on HBO Max is part of a larger trend as parent company Warner Bros. Discovery largely divests from kids and family content, which was confirmed by a statement given by a spokesperson for HBO Max: "Live-action kids and family programming will not be part of our programming focus in the immediate future." The other DC Comics properties on the chopping block were "Merry Little Batman" and "Young Justice Season 5". In August 2022, it was shipped away to other outlets such as Netflix, Apple TV, and Hulu (According to Variety, Aug. 2022). On March 9, 2023, it along with "Merry Little Batman", were picked up by Amazon for their streaming service Prime Video (According to Variety, Mar. 2023) On April 26, 2023, it was announced that another Batman-related project titled "Bat-Family" which will follow the events of "Merry Little Batman" will be release on the service. (According to ComicBook, Apr. 2023)