Sigourney Weaver is not certain whether or not Avatar 2 will be completed in time for its release date. Slashfilm reports that the actress said she doubts the film will be ready by the time Fox has projected, which is late December 2018. Weaver explained herself in the statement below...
“We haven’t started it, so I don’t know how realistic that date is, but I think it’s going to be very exciting,”
Considering how much time they'll need for filming, post production, and any hiccups along the way, I'd say that's a more than fair statement. I've just subscribed to the frame of mind that the earliest we will see the film is 2020. It keeps me from being disappointed at least!
Also, so what if it gets pushed back? Are any of us eagerly awaiting the release of Avatar 2 that much? I liked the first film, but they're going to have to bring more than next level animation to pull me in for a sequel.