No matter how many outlets have reported that Gotham City Sirens has been canceled, rest assured that a new report has the project still very much alive!
It was recently revealed that Warner Bros. had a movie featuring The Joker and Harley Quinn in the works, with Glenn Ficarra and John Requa (Crazy, Stupid, Love) in final negotiations to write and direct, and Margot Robbie and Jared Leto set to reprise their Suicide Squad roles. Variety reported that the project "appears to have superseded" Gotham City Sirens, but Jeff Sneider of The Tracking Board seemed more confident about the replacement:
This project would come on the heels of the characters' reunion in Suicide Squad 2, and would take the place of Gotham City Sirens, which has been re-conceived. That means that David Ayer is no longer attached to direct any movies in the DCEU"¦thank God.
However, Mark Hughes from Forbes confirmed that the DC Extended Universe project would NOT replace the David Ayer project. Both are in development, and the studio is "committed to bringing both to fruition on the big screen when the time is ripe". According to a studio insider:
Harley, Catwoman, and Poison Ivy are super important to us, and a super cool team, too!
Despite the fact that the Gotham City Sirens announcement came before the one for the Joker/Harley Quinn movie, Hughes SPECULATED (so it’s not written in stone) that the latter may arrive in theaters ahead of the former. Considering that The Joker broke into Belle Reve prison to help Harley escape at the end of Suicide Squad, sending the two lovebirds on a crime spree seems like a natural way to follow up.
The pair’s eventual break-up could very well set up Harley's decision to move on from her Puddin' to team up with Poison Ivy and Catwoman in Ayer’s flick. But that’s nothing more than speculation at this point, and it may not be what Warner Bros. has in mind.