I don't even know if we'll get ZX3 at this rate.
But, ZXA did set up ZX3 in an interesting way. Just like X4-6, you could possibly choose which Biometal (Z, X, or A) to use and each one could have its own story arc and they all converge. As far as people go, though, man, who knows. This whole Vent/Ashe, Gray/Aile thing was already out of hand, and ZXA made it worse!
I still want ZX3, though, badly.
And I still say Hareng was the other Chosen for Model Z!