He is working on a few chapters at once, but as far as I can tell he only streams one of the chapters ( Emily's). He works on the game during his job time too sometimes. That said, looking at the streams, he has been working on the same scene ( Emily Ch2 Scene 2) for the past month. I assume he is working on several scenes at once though, like the chapters.
So he does take a while with his process. He keeps finding new things to add to his process too, which I understand him wanting to do but it can be frustrating. Blender work, substance painter, looking into animations etc. So yeah, I don't expect this to ever get regular updates. Which is kind of ironic, since he made the game auto-code itself more or less so development would go faster. Adding more to the art process will easily cancel any of that out. He has the same issue a lot of developers have, they overcomplicate their art process with steps that may be neat, but unnecessary.
m0us3r
the v2.0 is new content. It just contains Cassie's new chapter though. It'll eventually be merged into the rest.