With the entire DC Films slate currently in a state of flux, it seems that Warner Bros. is doubling down on the one superhero that's almost always worked for them in the past: Batman.
The studio is currently in various stages of development on several DC projects either centered on the Caped Crusader himself (The Batman) or about characters in the greater Batman universe (Birds of Prey; Batgirl; Suicide Squad 2, The Joker & Harley Quinn; Nightwing; Deathstroke). While it remains to be seen if/when any of these aforementioned projects will begin production, rumors about each have been circulating for several months, if not years now.
The latest buzz comes to us from the always-reliable Justin Kroll, of Variety, who shared that his sources have indicated to him that the Penguin may be the primary antagonist in Matt Reeves' The Batman. He adds that if Reeves, who is still in the midst of penning the script, opts to go in a different direction, then the villain may be used as the lead opposition in Cathy Yan's Birds of Prey, which will also return Margot Robbie as Harley Quinn.
Regardless, based on his comments, it does seem that both The Batman and Birds of Prey are still quite a while away, with both most likely not commencing production until sometime next year, which means they won't be debuting in theaters until 2020 at the earliest.
Suicide Squad 2 is expected to begin filming shortly after Birds of Prey wraps, so there is a small possibility that WB could release three DC films in 2020 - maybe four if The Flash solo feature also meets its production start date. In the meantime, however, James Wan's Aquaman is due out this December, David F. Sandberg's Shazam! is out in April 2019, and Patty Jenkins' Wonder Woman 2 just recently began filming.