Nickelodeon and Paramount recently announced that three new animated movies from the world of three animated movies since Avatar: The Last Airbender's original creators Michael DiMartino and Bryan Konietzko are producers of the movies, even though they departed from Netflix's project.
The movies will be the first official animated Avatar release since Legend of Korra, which ended in 2014. Although Korra was generally well-reviewed, it failed to hit the same heights as The Last Airbender. Nonetheless, it certainly reviewed better than M. Night Shyamalan's live-action movie, which could suggest that the Last Airbender universe lends itself better to animation than live-action. While living up to the original Last Airbender will always be a tall order, there's one issue that the movies must address in order to stand a fighting chance.
One widespread criticism of Korra that the new animated movies must avoid is its worldbuilding, or, more specifically, the pacing of its worldbuilding. The Legend of is a sequel to The Last Airbender, with Korra being the Avatar that directly proceeds Aang, the protagonist of the original series. Although Korra only takes place 70 years after The Last Airbender, the world develops immensely. In the original series, the world is reminiscent of feudal Asiatic cultures, with the exception of the advanced Fire Nation ships and aircraft. However, in Korra, the first season takes place in Republic City which is highly advanced with an abundance of accessible vehicles, skyscrapers, and advanced governmental and societal systems. This advancement was criticized by audiences, breaking some viewers' ability to suspend disbelief. If the new Avatar movies take place in a future beyond Korra, this could only exacerbate the problem.
If the movie chooses to focus on events after Korra's lifespan, perhaps out of a desire to construct entirely new lore, then the technology would only advance beyond what was seen in Legend of Korra. Yet, the more modernized the society, the more detached it seems from The Last Airbender, and the more dissatisfied returning audiences would become since the series would not have listened to critiques of previous entries. While the movies could be set in the future and the creators could purposely halt the technological advancements, it seems like an unnecessary headache.
It's important to note, however, that the new Avatar movies are still in early development, which lends flexibility to the projects. The stories are not likely to be set in stone at this point, and so this problem could be addressed or avoided entirely. One way to avoid The Legend of Korra's problem is to set the Avatar movies before the events of The Last Airbender. The Last Airbender universe has a rich tapestry of lore, from snippets in the animated series to its extended media, such as F.C. Yee's novels. Before Aang, several named Avatars already hold relevance with the fandom, such as Avatar Roku who features in The Last Airbender, or Avatar Yangchen, the focus on Yee's novel, The Dawn of Yangchen. A movie focused on Avatar Kyoshi, who appears in The Last Airbender and will appear substantially in Netflix's Avatar, would be a hit with audiences. There are rumors that one of the three movies will focus on Kyoshi. However, nothing is confirmed. What's crucial for the Avatar movies is that they focus on the past, while bringing the stories back to a setting more similar to what was seen in The Last Airbender.