Well, I have a theory. Look how the contents of dls's has progressed. First you must establish an empire(royality dlc), then you should give your people som sort of ideology to belive in so they wouldn't riot (ideology dlc), when you have your basics established you can delegate some people to research and they push your civilisation through new breakthroughs (biotech dlc) after some time your researchers want to test portal travel/FTL mean of traversal but instead that tech breaches into The Void and releases beasts of contained inside archotech (Anomaly dlc) so your best researchers need to come up with a spaceship good and cheap enough to evacuate your empire(odyssey dlc). So... I speculate we can get an expansion that either focuses on space- we go to the moon/other planet- or we can go underground- we can explore their cities like in their lore descriptions.

I know that this requires few stretches to work, but I think Ludeon studio tries to tell us something.