In fact, there’s already an example of this in the DCU. Batman appearing in Creature Commandos is exactly this. They don’t know who is playing Batman yet, nor what the specific story of his film will be, but they know they are going to make a Batman film. Batman is out there. So that’s why that got a tease.

James Gunn opens up about which of the announced DC Universe projects has been challenging to finalize. Following their initial announcement in January 2023, several movies and TV shows from the DCU's Chapter 1: "Gods and Monsters" slate have gone forward.

Obviously this doesn’t mean that James Gunn’s new film, Superman, won’t feature end credits scenes – but we now know going into the Man of Steel’s latest cinematic adventure that any teases of the future the movie may contain were given special consideration before their inclusion in the finished cut.