It's obviously unknown if the information is legit, but Jamie Dornan is said to possibly be getting replaced on the Fifty Shades of Grey franchise. Maybe Jamie Dornan is going to play the new Green Lantern Hal Jordan for Zack Snyder in Justice League?
It is possible that Jamie Dornan could still sitck with the Fifty Shades franchise and play Green Lantern at the same time as he could film small cameo roles for Justice League and wouldn't be needed for the Green Lantern Corps movie until 2019 or 2020.
Per the norm, consider this a big rumor for now.
"Justice League" has a November 17, 2017 release directed by Zack Snyder starring Ben Affleck as Batman, Henry Cavill as Superman, Gal Gadot as Wonder Woman, Jason Momoa as Aquaman, Ezra Miller as The Flash, Ray Fisher as Cyborg, J.K. Simmons as Commissioner Gordon and Willem Dafoe an Atlantean, Nuidis Vulko.
Synopis:
Fueled by his restored faith in humanity and inspired by Superman’s selfless act, Bruce Wayne enlists the help of his newfound ally, Diana Prince, to face an even greater enemy. Together, Batman and Wonder Woman work quickly to find and recruit a team of metahumans to stand against this newly awakened threat. But despite the formation of this unprecedented league of heroes—Batman, Wonder Woman, Aquaman, Cyborg and The Flash—it may already be too late to save the planet from an assault of catastrophic proportions.