We have stopped showing to users who voted to close a question*, and yet for duplicates, we still advertise it with a (now brand new and even longer!) autocomment. We should start attributing these comments to the Community user instead. It is already used to post review comments depending on the situation, so this wouldn't be that big of a change. This would also help low-rep users for whom comments are automatically generated on flagging, but they lack the privilege to edit them.
If the poster isn't permitted to start arguing with a random user about a vote to close as unclear or too broad or any of the site specific reasons, then why do we grant them this ability for duplicates via this autocomment? Being able to possibly, maybe, perhaps convince a single user retract their vote is definitely not that important, if the same doesn't apply for other votes. That this "ability" evolved as a side effect of the workaround used for a deficiency in the system doesn't in anyway make it an actual necessity, or even the defining reason why it existed in the first place. It definitely doesn't justify keeping this "ability" around just for duplicates. If anything, duplicates are the most helpful of the close reasons and this misfeature makes it the one most likely to cause headaches for the close voter trying to help.
* I know they can still find out who reviewed their post.