Mity hinted that will bring new characters to this route, perhaps Kya, Opal and Kuvira. If that's the case, Mity has two ways of following the story of that route.
The first, making the narrative line be the same as the slave route, but bringing all these characters, ignoring the timeline, as he did with Toph, after all, Toph only appears in book 4 of the legend of Korra.
The second is to tell the story in another timeline, with new scenarios and different designs for some characters like Jinora (older) and Pema (thin). It is not impossible to happen.