> Delete Reaction Comments is an Always Be Closing (ABC) feature that deletes comments from pull requests that are better expressed as GitHub reactions.
Yeah. Recently (past half year) GitHub enabled a feature where duplicate comments are automatically edited to be hidden comments. I think it's a continuation of the GitHub feature that allows repository owners to hide a comment. Two caveats: (1) you can't hide a comment using the GitHub API; (2) I haven't tested whether duplicate comments trigger an email notification. Ideally they would not trigger notification.