1st edition ended with Nagash doing his big spell and starting the Soul Wars, so it focused (somewhat) on Shyish
2nd edition ended with Alarielle doing her big spell and starting the Era of the Beast, so it focused on Ghur
If the pattern follows, some big event is going to take place in the next (and final?) Dawnbringers book. I don't think there are any significant narrative hooks that strongly point to any particular realm... the crusades aren't even in Ghur. I do think Chamon seems the most probable of all the options, given the connections to Tzeentch, Skaven, and Grungni.
But maybe we just stay in Ghur