According to my supplier the next Dust Warfare Campaign Book will be Hades.
Here is the description…
The war for the doomed city of Zverograd heats up in Campaign Book Hades, a supplement for Dust Warfare! The pivotal battle has dragged on for months, and all three factions now seek any means of breaking the stalemate. Campaign Book Hades includes new unit stats, rules for superhuman characters, never-before-seen special abilities, and Tesla weaponry. What’s more, this jam-packed resource features the epic Hades Campaign, a long-term conflict in which players plan their engagements using a detailed overland map of Zverograd.
And the product number: DWF03.
I don’t have any further details, as FFG has yet to make an official announcement.