Adding my 2 cents - I'm chief developer for a forum software package (not this one)
Usually the poster's screen name is stored as part of the message along with their user ID - this is so that in the event a forum allows guest posting, the guest can use a screen name. Usually guest messages are also flagged internally as such.
Forum software usually determines whether a poster is a current member or an ex-member (unregistered) by if it can locate data for the User ID. If it can, that person is registered and the software will create a link to their profile. If not, then they are ex-members.
So, from where I'm looking, the software here is working properly - Suggs is an ex-member with valuable contributions rather than a spammer (the global delete function as described is designed to get rid posts by spammers).
In fact, in theory, should Suggs choose to return, it should be possible for him to use his old user ID and with (possibly) a few admin edits, get all his posts linking to him again.)
Of course, you COULD (maybe) ask for a mod that would replace the Screen Name with 'anonymous' for ex-members.
