His passing seemed sudden and unexpected. I have a recollection that he had mentioned some chronic health issues which prevented him from working full time, if I am remembering correctly, and another post in the thread mentioned a heart condition.
A post in this thread from another member described him well I think:
No matter what forum drama was going on, he always remained even-tempered.
I'm looking at his profile. That reputation score says something in itself: Reputation:+3833/-398
I would expand upon Sean Johnson's excellent idea of having Matthew contact whoever alerted him about Matto and have them let his family know about this thread, as they may find comfort in knowing how much he was appreciated and respected here. Perhaps also the text of this thread could be compiled into a file (such as a pdf) and sent to the family through Matthew's contact. This is what funeral homes do with the online guest books they typically have on their web sites.