They could have worked harder to say their remaining DCU movies were fun standalone movies, but muddied the waters with mixed messages about what actors were coming back and which movies were building toward the new James Gunnverse.
Most movies we watch are standalone movies. Theres nothing wrong with that. It often strains the storytelling when you try to stretch something into a larger universe (marvel has struggled a lot with that during this multiverse stage).
Just tell a good standalone movie and don't worry about what's happening beyond it. That's the message DC should have been pitching with its final movies of this dying universe.
Thanks and gig'em