At the moment there are no plans to move C&C to Steam. However, the next game we release, Walls Closing In, will be released on Steam. This will also be bundled with Northbury Grove and King's Comfort, so the complete trilogy will be on Steam.
We have ideas floating around for additional maps / scenarios for Cultists & Compounds. I imagine if we were to add a bit more content to this game, we will release the whole thing on Steam. But whether we pursue those extra scenarios or not will depend on the reception from the masses on this initial version. We're all itching to get back to work on Walls Closing In, we've got some really cool stuff mapped out for that.
Keep checking back here, on Twitter, or in our Discord for any updates!