Which if true, would mean we're nearing completion.
I think that's the OP's point. We don't know if that's true. I was active on my own forums long after I stopped developing my game, and "when it's done" became an inside joke as I lost interest in the project.
But I was still active on the forums for years after I stopped caring about/developing the game. I am well aware that is projection, and may not be the case here,
but it is an example of how being active on your forums does not necessarily mean you have intent of finishing your work, which is why people are spooked.
I don't see see how bugfixing and balancing means you don't need to post a changelog with some regularity. If you spent a month balancing missiles and market interactions, put that in the log. Even if that's all you did, and you can be as specific or general as you want. That way players who care about balancing and tweaks and the framework can read it, and the ones who don't can ignore it
while still being informed that it's under constant development from the mere fact that there are regular changelogs with things changing.
Also if you are in the phase of balancing, isn't that was your alpha testers are for? Isn't that the point of making your game available for purchase so early? Bugfixing and balancing especially are the quintessential reasons for having alpha/beta testers so that you have a wider set of players from which to pull statistics of what works and what does not. If you're only going to show things to your testers that you believe are full stable features, then it isn't really an alpha and it's more like an "early-access".