Confirmed. Great timing since the Flash movie is underperforming at the box office. Although people seem to like how Keaton is portrayed so maybe Muschietti has a handle on what to do with Batman.
Rumor is that the writer is gonna be John Logan (Gladiator; The Last Samurai; The Aviator; Sweeney Todd; Rango; Coriolanus; Hugo; Skyfall; Spectre; Alien: Covenant; Penny Dreadful).