If you visit https://lemmy.world/post/1181467?scrollToComments=true and check the post, the tiny comment icon under the post says that there are 5 comments. Checking the post however, you can see that there are only 3.
Is this some Lemmy bug, or does Lemmy shadow-remove comments like Reddit?
Could be. I try to plan ahead to avoid deletion since on Lemmy the post just gets a deleted stamp on it (the text may or may not be deleted so I always edit out the comment before deleting) and your username remains, leaving people curious.