DCEU: 9 New Revelations About DC's Future Movies

3. Birds Of Prey Won't Crossover With Batgirl Or Gotham City Sirens

So far, Gotham City Sirens is still happening, apparently and it had been assumed that it would feature Harley Quinn (as well as Jared Leto's Joker). But according to Forbes, there won't be a crossover between GCS and Birds Of Prey at all, and neither will the latter feature Batgirl in any way ahead of her own movie.

“For the record, Birds of Prey and Batgirl will not be tied together, for those who mistakenly believed the rumors that Barbara Gordon would have a continuing arc through both films. And there is not a Gotham City Sirens project crossing over with Birds of Prey, despite rumors to the contrary.”

The Batgirl project will indeed still go ahead, despite Joss Whedon leaving the project as director in the wake of his part in Justice League, so it's a shame we won't see her seeded before then. But at least it gives Birds Of Prey a real chance to shine on its own terms.

And as for Gotham City Sirens, it was always too close to Birds Of Prey anyway. The fact that it hasn't been cancelled yet shouldn't inspire any confidence that that news isn't coming.