Commits that are signed using a registered GPG key display the registered email address of the author even when the setting "Hide Email Address" is turned on.
Example: https://codeberg.org/dnkl/foot/commits/branch/master. Hovering on the green lock displays the email address even when their user profile doesn't display the same (meaning their "Hide Email Address" setting is checked)
I have seen this happening on one of my private repos as well
Not sure if this is a Gitea related issue because a repo on Gitea.com (using Gitea 1.14.0) with signed commits doesn't show the email address of the author.