The 2009 blockbuster that went on to become the highest-grossing movie of all time, bringing in $2.8 billion worldwide and winning three Oscars — was originally expected to hit theaters in December 2018. Director James Cameron has revealed that the major reason for the delay was difficulty
shooting the underwater scenes. Now that they have THAT mastered, they will be shooting Avatar 2, 3, 4, and 5. Cameron confirmed that the majority
of the underwater scenes will take place in Avatar 2 and 3. All four films are
being shot back to back, with December release dates set for 2020, 2021, 2024, and 2025. Can't wait!

i also read that if Avatar 2 doesn't do good!! then he wont make any of the Avatar sequels!! by the way i actually gave up on the Avatar squeals! cause one year he says it be out then he says next year then he does like 2 years!! so
so i wouldn't be surprised if they moved up Avatar 2!!