During the earlier days of the DCEU, word had been going around that WB was planning a standalone film for Kara Zor-El a.k.a. Supergirl. We haven't gotten any significant update on that film since, but word is coming out that WB has decided to put a halt with that movie.
According to Heroic Hollywood, an insider source has claimed that the Supergirl movie has been grounded because WB is currently trying to figure out a way to bring back Superman. While there have been rumors of Henry Cavill leaving the role, WB is said to be set on bringing his version of the Man of Steel back, seeing all the fan response on the internet.
Of course, we should all just take this with a grain of salt for now, but it does seem weird if WB would decide to make a Supergirl movie without addressing Superman. There has been a lot of fan support for Cavill to return, and it's only up to DC to bring his Superman into the "right" movie.
For now, it's been said that WB is handing over the Superman franchise to J.J. Abrams who had a Superman project he was working on before Superman Returns became a thing. There hasn't been a significant update on Abrams' involvement yet, but you can't really expect much counting that the Hollywood machine is currently tackling the global pandemic. Hopefully, before the year ends, we get some word on when we'll get to see Superman again.
In the meantime, catch Wonder Woman 1984 which is set to release on Aug. 14.