I recently encountered a rather confused but well-intentioned new member. This member asked a question that I and some others put on hold as too broad. The new member then added a comment to the question asking for clarification, but because the comment didn't @-notify any of the closers, none of us saw the question. I didn't learn that the member was confused until several days later when the member posted a follow-up Meta question asking about the post.
The close message instructs new users to "leave a comment" even though that comment may never be seen.
So that close-voters can help to workshop salvageable questions, they should be notified when the OP adds a comment to the closed question.