Sounds like a great start for a fanfic, but i am quite sure nothing of the sort is ever happening canonically. The Disney-relevant canon from what I can tell is meant as the endstate for the films to leave the universe in. I agree 100% with it myself, that is the most proper and "most Avatar" resolution. Dystopian futurism is frankly a dime a dozen, doesn't jive with the messages and the impacts of Avatar unless it appears as a transient challenger to be soundly defeated or destroyed, and we're probably already going to get enough attempts at darkness returning to Pandora in the next 4 Avatar films.
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