I think if Warner Bros were to attempt reviving Green Lantern (which I don't think they're interested in but anyways), they should take inspiration from what Marvel's done with Hulk.
Keep Ryan Reynolds or recast Hal Jordan, change the costume, make sure he has a very good role to play in Justice League - to the point where he is a standout of the film, like Hulk was in Avengers.
At this stage I see that as the only way we'll see another solo Green Lantern film in the future.
Thing is, they don't have to reboot at all. They just need to not directly reference the movie, but let people choose to see it as part of a series if they want to. In some ways (with the exception of the origin), Hulk and The Incredible Hulk can be read this way.