The script for Green Lantern isn't even done. I'm talking the first draft is still being written. Geoff Johns said as much at Comic Con, and I'm gonna take him at his word since he's both producing and writing. No way they're anywhere near casting yet.
Stop believing every rumor related to these movies.
Also, for those complaining about another white Lantern, the plan has been John and Hal since the movie was first conceived for the DCEU and Johns hasn't said anything to the contrary yet. So you'll probably get those boring ass lanterns you like.