That is demonatratively not true on github and gitlab, both having the ability to set an email alias which redirects the messages to your real email without revealing it.
https://docs.github.com/en/account-and-profile/how-tos/email...
https://docs.github.com/en/account-and-profile/how-tos/email...
1. git commits record an author name and email
2. github/gitlab offer an email relay so you can choose to configure your git client (and any browser-based commits you generate) to record that as the email address
3. github/gitlab do not rewrite your pushed commits to "sanitize" any "private" email addresses
4. the .patch suffix "trick" just shows what was recorded in the commit
When I said
> If you want, use a specific public address for those purposes.
that includes using the github/gitlab relay address -- but make sure to actually change your gitconfig, you can't just configure it on the web and be done.