You're almost certainly correct. It's the first thought that crossed my mind. The question you have to entertain is, "Why would MSFT release it if it can't be credibly positioned as an enterprise tool to begin with"? What CIO in his right mind would buy that? They're not much in the habit of buying "toys" for their staff to play with any more.
They'll have to get the missing features into the real release; it's worthless without many of those.
That said, I have a smartphone with about 20 downloaded apps, which is a very modest number by today's standards. Yet every day, one or more of them have an "update" available. New capabilities, added features, security enhancements, bug fixes. I've gotten used to the idea that software needs to be constantly updated.
I suspect Microsoft had two rationales: