Leak is the wrong term, and it’s doubtfully a deliberate marketing move either. More like, “suddenly being noticed because a bunch of GitHubbers followed the @AtomEditor account on Twitter”.
Also, despite the plethora of repositories, the actual editor is not available. It could be many of the public repos are public so they can be installed using their Atom Package Manager, which would likely have to jump through hoops if they were private.
That's correct, I'm the one who first found the project and I wouldn't call it a "leak". The site is live (domain registered by GH), the twitter account is live, the repo is full, the release is probably imminent.
Also, despite the plethora of repositories, the actual editor is not available. It could be many of the public repos are public so they can be installed using their Atom Package Manager, which would likely have to jump through hoops if they were private.