Thinking about Jet Lives AUs and how the only realistic future for Jet that I see is one in which he's completely and totally lost.
Every other character has something they can either return to, or a role they can step into. Sokka and Katara have their home in the SWT and their dad they e been reunited with, Zuko is coronated as the new Fire Lord for a new era, Aang has fully stepped into his role as Avatar and has a lot of rebuilding to help with, Suki has her Kyoshi Warriors to lead, Toph has the option of going back home to her parents or becoming a competitive bender- both are things familiar to her- or even becoming a teacher of her unique bending style and abilities. For the secondary and background characters, Haru has his home to return to, Teo can stick with his dad, Ty Lee joins the Kyoshi Warriors, Mai has her home to return to and Zuko to return to.
But Jet? Jet has no home and no family to return to. Not his blood family, who are all dead, and not the Freedom Fighters, who have disbanded. There's nothing for him in Gaipan, and I'd wager even less for him in Ba Sing Se but horrible memories. He's spent his whole life hating and fighting back against the Fire Nation that it became a core part of his identity. When the war ends and the Fire Nation pulls out of the Earth Kingdom and there's peace between the nations, what's left for Jet? His purpose is gone, he's got no path forward and no path home.
It seems reasonable to me that Jet might experience something akin to a crisis of identity or something.