It’s believed that at one point DC was planning on releasing an animated Batman Beyond movie, but because it was put into development by Walter Hamada, who was once in charge of the DC Universe.
According to John Rocha and Jeff Sneider, the movie was written by Dan Casey, but it’s unclear if we’ll see it, as it was commissioned by the old guard of the DC Expanded Universe.
James Gunn and Peter Safran have already canceled some DC projects to better shape their next reboot of the comic book universe.
The Batman Beyond movie probably wouldn’t fit into the timeline that Gunn and Safran wanted, as it would be a movie set in the far future, showing a completely different city of Gotham than we’re used to. But aside from Matt Reeves’ Batman universe, there might also be room for a Batman Beyond movie.