https://io9.gizmodo.com/a-convenient-guide-through-dcs-wild-and-uncertain-film-1829037379
Good article that looks at the craziness of the DCEU and beyond. So not only is there the above mentioned Joker but DC is planning a solo Joker movie with the Leto version along with a Joker vs Harley Quinn movie with Leto and a second Suicide Squad one that would focus more on the Joker as the bad guy.
Confirmed movies that are in the DCEU
Aquaman (December 21 2018)
Shazam! (April 5 2019)
Wonder Woman 1984 (November 2019)
Flash (maybe 2020)
The Batman (no release date)
Black Adams (no date yet)
Further off with no dates or might never be made but are still on DC/Warner radar
Supergirl
Batgirl
Green Lantern Corps.
Cyborg (release is not sure)
Birds of Prey (Margo Robbie's Harley would be part of it)
Gotham City Sirens (Robbie again this time with Catwoman and Poison Ivy)
Nightwing
Justice League Dark
New Gods (would be a different branch of the DCEU)
And finally, outside the DCEU there is Speilberg potentially developing movies about the WW2 era Blackhawks and also outside the DCEU would be Booster Gold.
talk about messed up planning etc.