Offhand I can't see any reason why he would go out of his way to N. Koreans advice on how to evade sanctions, so I will look forward to some statement on his part. 20 years is a long time.
I know he was working for the Ethereum foundation recently but doubt that the foundation would go out of the way to anger the US government (although they reportedly have a lot of Chinese government involvement).
Here is his twitter: https://twitter.com/virgilgr?lang=en