I suppose OP aparente001 wants to know why a user whose post (question/ answer/ comment) was removed due to flagging should not be sent an automated or manual explanatory message of warning such as
your comment [quote comment] posted on this question [link to Q] at 6pm on 33/13/99 was deleted after a flag was raised regarding its inappropriate content. Kindly avoid posting comments that are derogatory, inflammatory or abusive. Please read the site guidelines [link to be nice policy] for more details.
I agree with OP that such a message might be sent to the commenter who was disciplined, without making it visible to the community. It might be even sent 2 days after deleting the comment, if the intention is to avoid an escalation of unpleasantness. This type of feedback would help an inadvertently aggressive user to modify his/her posts to conform to community expectations of politeness.
However I am sure an intentionally malicious person would not learn anything from such feedback, in which case all the 'disciplinary due process' steps involving moderators mentioned above would be needed to take care of the problem.