Of course for small projects it won't happen. But for big ones it happens for sure. And then it doesn't matter if that (or these) repos are by the original auth

Of course for small projects it won't happen. But for big ones it happens for sure. And then it doesn't matter if that (or these) repos are by the original author or not. If you can rely on regular updates to that repo then people will use it just as if it would be the original source and will spread just as far as any other repo based FOSS project. So I think for major projects the limitation you can achieve that way is minimal.