Forking a git repo is not the same necessarily as forking a project for release.
The rules around naming and code reuse are more a matter of that projects particular licence. In git, a fork just means you have a copy of their code in your own remote repository, it says nothing about the licensing or how/if you can release your own version of the project.
We use forks at work - each developer works off a fork of the main repo. Has nothing to do with releasing different versions. It just keeps the main repo clean, and avoids the need to setup rules about who can push to which branches, because each developer owns their own remote copy.