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.

DC Studios, led by James Gunn, focuses on integrating key plot points into films instead of using post-credits scenes as teasers. Gunn emphasizes granting writers creative freedom and avoiding unresolved cliffhangers to ensure movie quality.

James Gunn recently gave a group of reporters a status update on the DCU at a DC Studios presentation. Among many other tidbits revealed, we learned that Gunn is already hard at work scripting the next DCU movie he’ll direct after Superman. He’s certainly keeping very busy these days.