Obviously, no one has any idea when the next version of this is going to occur. There are all sorts of rumors floating around steam about how broken the build is, etc, and it is really difficult to tell what exactly is happening. I have heard wide ranging rumors from the upgrade to Unity 2017 screwed it up to all the programmers did their own branches for a year and then they all tried to merge together at once. I doubt the real story is known and it is all speculation.
To keep with that tradition of confusion/lack of information, a previously locked thread on their website got an updated post 2 days ago:
The referenced second post section is this:
This is the entire thread in question: