Geomancer would fill me with glee, and it feels like a hint after the one in AST's questline (he even uses a unique weapon just like Arcanist in 1.0 had), but SE knows how badly we want dancer after the intense speculation that Lyse was one in the Stormblood reveal trailer.

But, I fully expect 5.0 will bring a tank and healer, since we need new ones now, and building 2 jobs seems far easier for the devs to handle than Ninja in the 2.x patch cycle, followed immediately by Dark Knight, Astrologian, and Machinist in 3.0. Both Red Mage and Samurai feel far more polished and balanced.