@PitaJ Thanks, it is actually not the issue of NodeBB, it is the decision on which strategy to choose. Anyway, I've done no worse than before, that is enough.
A user in our forum reported the below feedback to me, and I agreed that this is really ugly and hurt user experience:
I just viewed a topic without being logged in and I saw a post I deleted still showing up, with the body "This post is deleted!". I think that's rather ugly and that deleted posts should only be visible to the author and admins.