- Shakturi expansion will be next major update ("early 2024" so hopefully Q1). We know very little about what it might actually contain beyond the Shakturi end-game threat. (Personal fingers crossed for alliances/more diplomatic gameplay)
- Human/Mortalen revamp "almost done" (personal fingers crossed for human female art, but the revamps are focused more on content than art assets, so...)
- Boskara/Zenox revamp "next in line" after Human/Mortalen
- No known ETA for the remaining base factions (including my favorite Teekans

- Current beta patches include improvements like actual distance measurement tools and bug fixes
We also know that the Discovery update came with performance improvements on par with the magnitude of the Aurora update, while the next wave of performance tweaks (no ETA) will be of a magnitude closer to the Hyperspeed update.
We know that the next two factions for DLC have been selected internally but not announced, and no ETA.
We know that Steam achievements are on the docket for some future date, but no ETA.
Other major features from DW:U such as playable pirate factions have been mentioned as things that the devs would love to bring to the game at some point, very likely as major expansions like the upcoming Shakturi expansion. There have been no announcements as to what the next major expansion (after Shakturi) will feature or when it might be in development.
I'm sure there are a few other hints I could have gleaned, but I think that mostly covers what we know about the unofficial roadmap at this time. Cheers!