I see one major pro to this feature. I've often seen users get harassed over their vote to close as a duplicate by some unsavory users, which may include revenge downvoting. I've also seen cases where it's not harassment but a user continues to try and engage with that user, who just wanted to close as a duplicate and move on, and didn't want to start a conversation.
However, I can see a couple major cons to it:
- About half the time when I vote a question as a duplicate, I edit the automatic comment to explain why it's a duplicate (e.g. what answer/part in the target addresses the question). If the comment were to be attributed to Community, I wouldn't be able to do so; I'd have to leave another comment which would anyway give me up as the one who voted.
There's currently an ongoing bug where comments posted by the Community user cannot be flagged, which means that if the comment were to go obsolete (e.g. the question wasn't closed), no one can flag the comment for deletion. (This was part of a feature experiment whose code wasn't completely removed.)Also, the voter cannot delete the comment on their own.
If this is to be implemented, I'd present an option to the user as to whether they want the comment to be attributed to themselves or to Community.
However, if that's the implementation, it's probably better to have it instead be an option as to whether or not to leave a comment at all. The comment dates from a time when the system wouldn't show pending duplicate votes to users at all - now, the system shows them clearly and gives the user the option to self-close. This, on its own, makes the comment entirely unnecessary if the user isn't going to participate in the discussion or edit the comment to explain where/why it's addressed. The only thing that this would remove is the notification upon the first close vote, triggered by the comment - but that can be implemented explicitly.