According to the newest episode of Heroic Insider, hosted by Hollywood producer Daniel Alter (The Apparition, Hitman: Agent 47) and Heroic Hollywood's Umberto 'ElMayimbe' Gonzalez, DC Entertainment Chief Creative Officer Geoff Johns and Oscar winner Ben Affleck will have "complete creative control" over the solo Batman film. Which logically indicates that Zack Snyder, Deborah Snyder, Charles Roven or any other frequent DCEU overseer has no say on what Johns and Affleck ultimately cook up. Alter and Gonzalez further report that Affleck is taking the lead and Johns is more of a consultant, providing necessary references to comic book lore and not necessarily shaping the story.
After months of speculation, WB recently confirmed that Affleck will indeed star, write and direct the solo Batman film. The film is currently without a release date but Warner Bros. has snagged two dates in 2018 and 2019 for future DCEU installments. It's probable that one of those dates will be given to the standalone Batman film.