I know with all the uncertainty going off with Itch, this is going to be the last thing on your mind. But if you can't post future updates on here, or even decide not to, can you look into how people who have paid for the game already can continue to get the updates?
Viewing post in Questions about Stranded in Space
Steam doesn't support Android as a platform.
It's possible they'd be OK with you putting up the Android version as a free-for-purchasers downloadable extra (as some games do with soundtracks, art, etc), but I suspect they'll say no. I've never seen a game on steam do that, and I doubt I'm the first person to think of it. Plus I've already thought of a couple of problems with it, so yeah, I don't think that's happening.