Kevin Conroy's final performance as Batman following his death in 2022. The movie is dedicated to his memory after the ending credits.
The last performance of Mark Hamill as Joker, due to his retirement for voicing Joker because of Kevin Conroy's death in 2022.
The final chapter of the Tomorrowverse of DC Comics animated features, which started with Superman: Man of Tomorrow (2020).
Constantine is the only one besides Spectre to be aware of the DCAMU.