jk.
But this is my opinion and this will sound really bad but... Famous people should really be the only ones to have a leaving thread. A lot of people know this famous person so therefore many people would come out and say their piece: The goodbyes, The thank you's, The god I hated you's. The thread would become very popular and maybe even the leaving person would feel slightly better about their passing.
Now for non famous people. They most likely do not have many forum friends or followers, so it would be pointless for a thread and would just create more thread spam and people shouting nobody cares. Only maybe 1 or 2 messages would actually be from friends. This is where the status' come in. They make one, say they're leaving then the friends know without any hassle and disrespectfullness.
I may sound harsh but really.... no one actually cares about these people except a few, whereas with famous people many people care about them.