Maybe there's aspirations to not be a "smaller programming language" and he'd rather not cause confusion and burn interested parties by having it available.

Releasing it when you're not ready to collect any upside from that decision ("simply ignore them") but will incur all the downside from a confused and muddled understanding of what the project is at any given time sounds like a really bad idea.

In that case the release interval can be tweaked, just frequent enough to keep people interested.