A moderator (in this case me) deleted the user in such a way that the community user (a bot) deleted all the content of the now deleted user. In most cases it does not make sense for an automated message to be attached to the question as only 10k+ users can see the deleted question. As a high rep user, you should just assume that if the community bot deletes a user and all their content, there is a reason for it. If the community user deletes a single question/answer, it leaves a message that says the post was rude or spam (10k+ users can look at the message on this awful answer, I cannot find a community deleted question for reference).
When a moderator decides to delete a user, the decision is not based on any individual question or answer from that user. We also have choices about how we delete the user and what to do about their content and votes. If we decide to delete a user and their content, we generally do not know what will be deleted by the community bot when it cleans up for the user. Therefore, retroactively giving explanations would be really hard.