> If the email matches their GitHub account, GitHub links the commit to their profile and grants them contributor status.

When the article mentioned email matching, I was concerned that it would break down when a contributor's email address changes. (I have contributed to more than a few projects over the years, using email addresses that no longer exist.)

However, it looks like they're not using the email address recorded in the author's original git commit, but instead a GitHub-generated address whose unique parts are the GitHub user ID and username. That should survive authors changing their email addresses. It would still break down if a contributor loses access to their account and has to create a new one, but that's probably less common.