My thoughts are that Bo married Opal and had kids that were benders of air and earth. I also think he trained more in his earthbending and fully perfected his lavabending which caused him to want to teach other earthbenders how to perform the skill. I believe that sometime in the future, he was ale to learn metalbending as well after being told by topth that he can learn it. I think he will probably try to train with toph but she gives him advice and he finally gets it. I think Korrasami is going to be longlasting and maybe they will adopt. Asami will continue with her invention prowess and help rebuild republic city and expand to the earth kingdon. Mako might end up marrying as well and I feel like he will eventually become chief of the police force. So what do you guys think?