6 days ago, he shared a post on Patreon telling as to why he wasn't done in the time he had projected from a post he had made in October saying he'd be done in October or Early December.
So that post 6 days ago he details exactly what had been going on, the fact he'd been working on it tirelessly and with little breaks, and the fact the update is a pretty large one. As you can see at the bottom of the description, this version is longer than all previous updates combined, and that it is now CURRENTLY in alpha build, being tested for bugs. So it should be in beta, then early access, before finally being pushed out into the public in (I'm speculating) perhaps the next month.
All of that information(except for the small speculation, which anyone could make) is free for you to read on this page, the patreon, and probably also in the Discord.
I guess what I'm trying to say here is, if you really want to see if the story is being worked on, you literally have means to find out yourself.