I'm confused. Hasn't the Librephone been in stalled development for over a decade?
In contrast, Librephone has only been aannounced this week, and it attempts to reverse engineer stuff related to device firmware and binary blobs. It's not the same as creating another Android distro, and any usable results won't be tied to Android, so they for example can be used to give better support for mobile non-Android Linux efforts.