I've just read that the UCI has again changed the rules on bikes for the hour record, it's now a complete mess regards to previous records!
Apparently, the new rule is the bike has to be UCI legal for a pursuit bike according to whatever the rules are currently, and the distance Voight had to beat was 49.7km set by Ondrej Sosenka (which was called the athlete's record, on a bike similar to Merckx's, which both are still UCI legal, I presume).
This means the "superman" hour records don't count because the position is not currently UCI legal.
But what about Rominger's record of 55.291km? As far as I can see, that was set on a bike similar to Voight's, ie tri bars and disc wheels. It seems the UCI are saying Rominger's bike is not currently UCI legal.
So I don't think Voight has beaten the hour record!