I've been involved with a lot of community/social media type websites, with the longest such hands-on involvement being 5 years as an admin on one of the better known webmaster forums, Cre8asiteforums.com
Never, ever, have I seen any such site where hitting the submit button on a post doesn't mean they own that post now. Its the most basic and fundamental thing. In fact, the removal of posts made, after the fact, is a form of bait-and-switch that has been a completre faux-pas in Nettiquette guides since the days of BBS and newsgroups.
Removing all of your posts in a fit of pique is like demanding everyone pretend you never ever said anything, and that every conversation anyone had with you should now be redacted. It is incredibly rude and petty. It rates far above Godwin's Law in the scale of such things.
Removal of all of a user's posts is very, very rare. Because that dismisses and annoys every single member of the community that replied to them, and now has no context for what was said. Demanding such deletion is beneath contempt in terms of how in insults and annoys everyone that is part of the community you chose to post to.
Now, I wish that stating this were not going to be seen as an attack on Gangrel, and would not upset his girlfriend, and my friend, Kallandra. However, these are basic facts, and if they happen to apply to Gangrel, that is his doing, not mine.