Based on the slew of other DC movies in the works, it is obvious some type of Justice League movie(s), similar to The Avengers is(are) in the works. The Court of Owls doesn't seem to have any affiliation with the League, or enough power to warrant the League's intervention. As shown in the first two volumes of Snyder's Batman, the Bat-family alone can handle it. The planned DC movies all seem to feature members of the Justice League. There wouldn't be enough time to introduce all of the Bat-family and have the entire Court of Owls confrontation in one movie. Also, it seems unlikely the writers could convincingly write the Court of Owls in such a way it required the Justice League. This would not only come across as contrived, but do a disservice to the comics.

There's no room for a stand-alone, live action Court of Owls movie in DC's plans for the Justice League to appear on the big screen. They aren't going to devote the resources to a stand-alone movie, despite all of the fans that want it, because DC is banking on the slew of Justice League related movies performing better at the box office.

The Court of Owls arc is one of my favorites of any comic, and I'm not sure I'd like to see it adapted. It has several themes and nuances that make it great that I'm afraid would be lost in the conversion to the mainstream live-action format. At best, I would get a perfect rendition of a story I already enjoy, forgoing the possibility of enjoying an original story for the movie. At worst, I would be extremely disappointed in the movie version of the Court of Owls.