This seems to be about GitHub’s annoying CODEOWNERS feature where every matching user in the CODEOWNERS file is forcefully added as a reviewer of opened PRs.

To my knowledge this “feature” can’t be toggled independently and in my experience often drastically reduces the signal-to-noise ratio of GitHub notifications for people in a CODEOWNERS file.

I wish GitHub allowed this to be configured. You either get this functionality and enforced code owner approval, or neither.