Unless you post the new source link, it's hard to understand the real situation, because sometimes we fail to express our opinion. Hackers won't send Bitcoins to the government; otherwise, why would they have hacked? Rather, the government probably seized Bitcoin from the hackers somehow. Unless hackers mix Bitcoins, then it's pretty easy to know from where these Bitcoins came from.
Regarding with this, it is said that the hacker returned the bitcoin to the government. So I guess it is their right to do whatever about the stolen bitcoin. It will also be a long process to track every address to it's rightful owner.
Bitcoin Blockchain keeps all the records of transactions, and it couldn't be destroyed. When the government seized something legal in the country from someone, then they definitely returned it to the right owner unless it was involved with criminal activity. Like your mobile phone being stolen, one day it is seized from the thieves, and then the legal authority should return it to the right owner. So unless we read the full news, we can't say something. Governments don't have the right to sell my assets; they could sell only unclaimed confiscated assets, though each government would have their own rules.