Though it has not been formally announced, Keston John, CJ Jones, and Chloe Coleman have been cast in the Avatar sequels. Keston plays Va'ru, and Chloe plays Young Lo'ak. CJ's character is unknown at this time. He is actually a deaf actor. He lost his hearing when he was seven. He has been advocating for more disability representation in Hollywood. He developed sign language for the Na'vi. This means we will likely meet Na'vi characters who are deaf or hard of hearing. I wouldn't be surprised if Na'vi sign language turns out to be very similar to human sign language.
https://james-camerons-avatar.fandom.com/wiki/Avatar_2