For newer users, the 3 day no poop post was an legendary asklemmy post where OP asked how they could go three days without shitting. We never found out why.
Two other possibilities. 1) the user did it, or 2) the user started posting some crap, got banned, and lemmy’s trash mod tools encouraged “delete all posts.” Lemmy mod tools are truly garbage.
Yes, if it was removed by a mod. If it was deleted by the creator, then no.
Also strictly speaking maybe no if the admin of the user's instance did some special fuckery. Every post or comment is hosted first on the user's instance, then federated, so if the user's instance is running altered lemmy code then it could do all sorts of funky shit.
Edit: @mizu6079@lemmy.world is still around, so maybe they'll come and answer. That should have sent them a mention, the instance agnostic link for them is /u/mizu6079@lemmy.world (if your app can handle those, it will be a link on the website). Seems like they deleted all their comments.
Edit2: The original post still exists for me: https://lemm.ee/post/241183. You'll have to browse their profile using the instance agnostic link to see if it's on your instance.
Edit3: I see nothing on the lemmy.world instance, looks like they wiped their account entirely. Yet their posts do seem to exist still on some other instances.
That's not the federated post, that's the current lemm.ee post - which won't include any of the user's comments (they are deleted on lemm.ee).
The federated post is always on the user's instance. In this case, even though the community it was posted in was lemmy.ml, the user was in lemmy.world, so that is the federated host. This is the link to the federated post, but it's been deleted so you just get an error: https://lemmy.world/post/440073