I wouldn't say that, they just didn't provide open access to their feature branches before they were merged (or "production-ready", however you want to put it).

> I feel like you missed the point of this discussion: the server code in fact hasn't been open source for the past year, and so one couldn't make a fork of it.

That seems to be overstating things. The server source in fact was always available, but there's nothing about open source that says a developer has to push their changes out on a particular schedule.

Also, it's supposed to be E2E encrypted, so I think the source that's really important is the client.