So looking for another potential DCEU release in 2018, WB current have these in develpment
Gotham City Sirens - In development for a year, could be fast tracked if the script is decent. Harley Quinn is a major draw, so best possibility for summer release
Nightwing - Probably a smaller film than the others. Could be fast tracked, but I am not sure it would work as a summer tent pole
Suicide Squad 2 - They should have a script by now. Not sure they should fast track this one
The Batman - Matt Reeves is available now for directing, but Affleck does not want this movie to rushed. I think 2018 is out of the question
Batgirl - Joss Whedon is tied up to Justice Leauge up until november. I don't think he can make the movie for 2018
Man of Steel 2 - Currently no script, no director. Too many effects for a rushed released
Flash - Script problem and no director attached. Too many effects for a rushed released
Justice League Dark - In development for ages. Could be fast tracked.
Wonder Woman 2 - Script currently being written. Don't think they can make it
Shazam - In development for a long time, The Rock is attached. Maybe they could move up the production.
I left out Cyborg and Green Latern Corps since they already have a date.
I think the best bet for another 2018 is Gothan City Sirens or Nightwing, but maybe it is just best to not rush anything. Waiting for Comic Con for confirmation.