In the first-ever case of its kind,
it is in no way the "first" case where the government seizes bitcoins from someone specially if that someone is a criminal. there has been lots of cases before this, Silk Road for the most popular and old example where FBI seized somewhere around $100 million in total if not more from those involved in it.
I was also thinking this would be the first of its king, I have actually heard of physical theft of bitcoin which some were apprehended and handed over to law, but dont know of apprehending of an hacker. The funds being seized by the government, i, are they refunding it back to the victims, or they would just seize it and add it to governments purse, if government was able to apprehend the hacker, then it should not be much difficult for government to regulate the cryptocurrency.
I am sure that it was through their kyc that they were able to apprehend those ones and we need those type of news to be on the internet in other to encourage some investors that are scared of their security and that of their money, at least there is chances that an hacker can be caught.