Forfeiture doesn’t mean destroying the coins. If the Fed can gain access to the coins they will auction them off.
But if I understand correctly, this is the Fed basically laying a legal claim to and flagging coins that it doesn’t control therefore making them much more difficult to redeem, after seeing that they moved, which implies a hacker did manage to crack a wallet.
This story is the perfect example for how little privacy is actually afforded by the Bitcoin blockchain.
It’s unlikely the Fed has access to the coins, and that’s why the Bitcoin price just went up 7% because whoever cracked the wallet certainly isn’t going to hand over the coins.
Either those coins will never be spent, or the hacker will have to find a country willing to launder them and somehow keep the Fed at bay (doubt it), or if you’re the Fed maybe you arrange a settlement with the hacker to split the coins.