I can't imagine Avatar getting a sequel made that does as well as the first one did, unless they make some changes or add certain draws, in regards to the writing. Then again, total crap like the Transformers sequels continue to make bank, so what do I know? maybe Avatar and its ilk are all that most theater-goers want.
I hope that the news about Covenant isn't true. It seems like it's not exactly from the horse's mouth, or a direct source.