Only adding the s and we'll get Jupiter moon
s making the theory possible again. Though I think it'll be more a stretch for the game. Judging from the current narrative and fictional achievements it would make sense to spreading out and constructing more infrastructure around Jupiter. Europe is easily one of the most interesting moons of Jupiter. Especially exploring the FoE-dimension in which aquatic alien life has submerged under the thick ice layers of Europe. That been said I think more players will like to moving on away from Jupiter afterwards or don't mind wherever we'll going as long more ages will be added to continue the game.
While I can understand why others would be disappointed and feeling like it's just cosmetic and an reskin. Actually I rather feel like the ages are an overall good package and exploring interesting SF suggestions in the space ages through this extend. To me the experience is pretty good. Though I understand others who are faster bored of fundamentally the same mechanics. I can see how spiced up colonies making the space ages more interesting for those who enjoy settlements, including myself, while others who don't like them hate everything they need from the colonies.
The biggest issue with the main city is that for the more successful players even before reaching Future era their cities are stacked with event buildings. Rendering any investment in regular buildings nearly useless and rather an event requirement to continue adding into any new age. An colony resolves those issues entirely by offering an fresh start each new age playing with different rules and objectives. Credits,goods production and discounts on set production.
Do I think they could vastly expand the colonies' mechanics? Sure they could and it's likely settlements are the pre-runners of the concept. Perhaps even the test drives needed to look what works and what doesn't. So, offering slightly tweaked mechanics unique to each future colony could offer new challenges and unique gameplays. Which could be justified narratively by dealing with entirely different environments and situational demands: militaristic, industrial, scientific, family friendly, exotic vacation destinations, wild experiments in an isolated place, etc. From an gameplay and developer perspective it could be easily argued as an way to satisfy the urge of continually changes in mechanics, gameplay and character of each new age. As per community demands. Which I personally would also dig tbh though we might encounter at times mechanics we don't like. Similarly to some settlement tweaks. Translating it 1:1 to colonies. SAM, SAAB, SAV, SAAJM(?), could be like the Vikings: vanilla mechanics to families with the concept and base mechanics. Later ages / colonies could be like Feudel Japan, Ancient Egypt, etc tweaked mechanics and unique gameplay.
