I'm currently reading "Eight Lamentations: Spear of shadows". I'm half way through and Dispossessed are their own thing as well as living together with humans and other races in free cities. All 3 dwarf races are also different to Grungni. That's why I don't think we will see dispossessed only I'm free city books, but in their own battletome.
At first I thought a combined duardin battletome could be a thing but after reading the book and listening to gotreks audio book, I don't think that will happen either. Fluff wise the duardin races are only similar in loving gold, beer and their size.