I bet she meets Amon and Tarrlock there!
It'd be even better if Bryke did a repeat of the "Avatar and the Firelord" episode, but this time it featured Aang taking Korra to his past, struggles, and success.
But Momo and Appa still alive, they are pretty old, but it's not confirmed that they died
So they died? :(
Probably, though I don't think it was ever revealed how young Momo was, and how long flying lemurs live, so he could still be alive.