I’ve recently noticed this happen to two of my comments. Both in cases in which I don’t agree with the deletion. Deletion without giving the possibility to appeal is unjust; but without notification is vile.
I immediately need to apologise for the strong language, and I’d like to stress that I don’t want to accuse or insult anybody. Nevertheless, I feel quite strongly that it’s a morally flawed system that should be fixed.
Let me explain why: Both of these (presumably flagged and then) deleted comments were in the context of discussions in which my interlocutor was probably wrong.
Of course I’m biased. But in one of the cases my interlocutor went so far as to revenge downvote several unrelated answers (the downvotes were later automatically undone, of course), and, after I alerted him to the fact that he was displaying inacceptable behaviour, he deleted his own offensive comment and … “vanished”.
In the second case I don’t recall what I could have written that would trigger flags (this alone would make it important to notify me of deleted comments! If only so I could see which behaviour is deemed unacceptable). But the interlocutor played me off with a (in my opinion) tacky
your comment was funny […] I think you misunderstood the question intent completely”
(I don’t think I did. The question was also subsequently closed as “not constructive”.)
I do understand that comments will be flagged and/or deleted, and that I don’t have to agree with that for it to be justified. But I do request the fairness and courtesy of being alerted to this fact.
Finally, an objection to the objection:
Comments are third-class citizens in our system by design
That’s all fine. But by not notifying the user you’re making the user a third-class citizen of the system. And if comments are outside the rules of fair play, then they are not a legitimate citizen of the system at all and should be removed completely.