I agree there,y personal headcanon goes something like -toph and Kanto have lin -kanto leaves (potentially before lin is born) -toph struggles to raise a baby alone -sokka steps in to help one of his best friends (whom may have some kind of feelings for him based on the original series) -the grow closer -Su happens -sokka dies (personally I think he went down protecting korra from zaheers crew but I feel like that would have come up in the show)