It is quite common that users with no rep. want to react to old questions. Many times it is something like: "I have the same problem. Did you find a solution?". They posting it as an answer and I'm flagging it as "Not an answer - should be a comment". I would also like to notify the user that he should post it as a comment next time but posting comments to questions is priviledge of users with 50+ reputation. At the moment I just adding comment that if the user have the similar problem he should ask a new question and link the unanswered one. But I'm not sure that user will see my comment if a moderator deletes flagged answer.
So how to handle these scenarios? Should be all users allowed to post comments to questions (or at least to old questions with not accepted answer)?