For the most part it affects nothing (except for settling beside the rest of our projects!). As per Github's documentation on repository transfer, every link is redirected to the new location, including issues, forks, and everything else that matters.
If you have a local clone of the repository, it would continue to function normally. Nevertheless, to make it less confusing, you should update your git remote URL.
git remote set-url origin https://github.com/postmanlabs/newman.git
If you're having any issue accessing the new repository, let us know.