Yeah they were supposed to be the start of the Dark DCU. That’s not happening now. If (and that’s a huge IF) another streaming service like Netflix wants JJ’s Constantine I can’t see them committing to Madame X and Zatanna too. They’re probably the only non-Disney service that could conceivably do that and they’re coming off a shaky year.
If they do go to another streaming service they aren’t going to be a part of the DCEU. I wonder if they have plans for Keanu’s Constantine to be the catalyst for the supernatural DC characters. Would be cool if the sequel introduced Zatanna. It’s not a tv show but it’s something.