Disney released their entire slate for the next few years. They’re going to alternate releases of each Avatar and Star Wars every December (2021 Avatar 2, 2022 new Star Wars, 2023 Avatar 3, etc.).
I wonder if WB releasing Dune only a month earlier had anything to do with Disney pushing Avatar 2 back an entire year.
Really doubt that Disney would be worried that the sequel to (as of writing) the biggest movie ever will face rough competition against a remake of a box office flop directed by the guy who just made a long awaited sequel that turned out a box office flop (I’m really excited for it though). More likely than not James Cameron himself is delaying it (or, the same reason it’s been delayed for the last five years).