Given that it seems like it's just one person, and he has had some health problems and a loss of employment, a slowdown (or closure) is not unexpected.
What he wants to achieve sounds really cool, but I'm always leery of single-dev OS's, especially when they're as ambitious as creating your own brand new codebase that's not downstream from one of the common Linux choices. Shit happens, even if it's just burnout, and if the devs aren't replaceable, project closure is almost inevitable.