Horsetan (according to EarlyRisers sometime ago) had a run in with A N Official and has gone completely.
Another one who vanished completely was Dutch Master who had a run in over meat labelling on ER.
Travellin Trev, from north Devon but living & working in Nigeria also vanished quite suddenly.
RM Web should have a cold store, where your profile slips into if it is not used for say, 6 months. It's not deleted but just stored in case you come back. That way we would at least know that someone may be MIA.