Matt Reeves is potentially terminally ill and has already quit on The Batman: Part II as a production grid leaked without him attached.
SGT. ROCK and CLAYFACE are cancelled. They were never "real" projects, just used as ploys to get "A-list" talent involved with the DCU to boost industry and public perception.
SUPERMAN test screenings have been "worryingly mixed" with neutral audience members being very dismissive of the film as a whole, not condemning but not praising it either. WB execs used MINECRAFT and SINNERS to promote it out of desperation.
SUPERGIRL was rushed into production due to WB/DC jumping the gun on Gunn's behalf. Ultimately, it might be canned like BATGIRL.
LANTERNS might have any and all DCU connections scrubbed if SUPERMAN doesn't entice people in following this new universe.
No other DC projects are in any kind of real development. Keanu Reeves wants to make CONSTANTINE II but without any DC Studios oversight, just like Todd Phillips with JOKER: FOLIE A DEUX. Understandably, WB is reluctant but his star power might sway them.
THE BATMAN: PART II and THE PENGUIN SEASON 2 are more likely to be scrapped than folded into the current DCU because there are many elements that Gunn doesn't approve of and Pattinson is unresponsive to the idea. THE BATMAN universe is DEAD.
SWAMP THING, THE BRAVE AND THE BOLD and all the other initially announced DCU projects are nothing but pipe dreams.
The DCU was a last-ditch attempt by WB to drum up interest in the DC brand so they can sell it off to the highest bidder. Zazlav is the one making this push. He wants to focus on the other IPs that WB has at their disposal.
Tangentially, WB has been trying to lure back Christopher Nolan back from Universal.
DC Studios have talked to a rising B-list director about doing a RORSCHACH project.
Joaquin Phoenix pretty much "ghost-wrote and ghost-directed" JOKER: FOLIE A DEUX. Todd Phillips was squeezed out of the movie.