No, it doesn't. The GPL does not stop anyone to release the code as a tarball instead of systematic commits to the repository, and you are only obliged to give out the code to users of your program. If it's only shown in demos and used in-house it's legal not to do so. It's bad bad manners anyhow, especially from an open-source company like canonical. I think there was similar behaviour from Apple with khtml/webkit, but they changed, too.