In this context I think they're referring to tools to automatically sync your git/wiki/releases etc from Github to other platforms like Gitlab.
The others, though, yeah. Those are handy.
Gitlab definitely does this automatically for you if you mirror the repository. Or am I misunderstanding how this feature works?
This made me think the gp was referring to Gitlab (pull sync) but you're right, they may have meant Github (push sync).
In this context I think they're referring to tools to automatically sync your git/wiki/releases etc from Github to other platforms like Gitlab.