I have been thinking about this a bit. Barring the delay for repackaging, etc. The way that the releases have happened is kind of interesting.
First, Daqan begins to see the stirrings of the Waiqar forces and engages to stop the tide of the undead from sweeping through the lands.
The Latari stir from their isolation to lend a hand. Since there has been little contact with Daqan in years, there are skirmishes between them, as well as the undead.
Finally, the demon horde erupts onto the scene, which none have seen in centuries. The strange powerful demon back armies run rampant through all existing hosts, as they are vile and unfamiliar.
Eventually there will be an equilibrium reached as tactics become familiar and counters are found.
This all feels like it's playing out with some thought behind them. There is a meta-story being told as the releases unfold. We are at the point of the story where the darkness seems to be overwhelming...