This is a touchy subject in our industry. I imagine most review board owners are very secretive about their personal affairs, so while his members would love to know the truth, I don't know if we'll ever find out.
At the same time threads about the email were being posted on terb and perb, Fred's handle was logged in and active on merb (I have screenshots).
So, if Fred has truly passed away, he would have handed his boards over to whoever he trusted to look after them, and they will have taken over his accounts.
If Fred is still alive, he obviously doesn't care that a whole lot of people think he's dead.
One thing I know for sure is that he would never sell his boards to the one who says he now owns them.