Current DC movies serve two purposes. First and foremost, they need to tell an entertaining story centered around the character in question. And secondly, they have to continue to make a connection to the existing DCEU, because characters like Aquaman (Jason Momoa) were introduced in Batman v Superman: Dawn of Justice, so we know there's a universe that contains all of these heroes. When CinemaBlend sat down with James Wan ahead of the release of his new Aquaman, we asked him about connecting his solo movie to the DCEU at large, and he told us:
For a while, DC chased what their "rivals," Marvel Studios, had. An interconnected universe of films that could cross paths on the occasion and all contribute to the same large story quilt. But with Wonder Woman, Aquaman and next year's Shazam!, DC is wisely moving away from that model and allowing their films -- and the hired filmmakers -- to work separate and stand on their own.
Wonder Woman, in particular, was a prequel that had a frame story tied to the DCEU, but really could work on its own timeline. The same goes for Wonder Woman 1984.
And while Aquaman has a line of dialogue that connects it to Justice League, James Wan's movie really was able to operate without having to set up the next DCEU movie, or fix problems from its predecessor.
Here's James Wan, talking about the process of connecting Aquaman to the DCEU, while also making sure it stands on its own.
In Aquaman, Jason Momoa returns to the role of Arthur Curry, but tells his origin story, which also includes the courtship of Queen Atlanna (Nicole Kidman) and the human Tom Curry (Temuera Morrison). Not only is Arthur dealing with a threat on the surface, he has to return to Atlantis -- a land he rejects -- because of the rise of a threat to his heritage, and his kingdom's throne.