All the wallets were drained years ago and [1] says the bitcoin "are already in the government’s possession, custody and control".
[1] https://storage.courtlistener.com/recap/gov.uscourts.nyed.53...
[1] https://storage.courtlistener.com/recap/gov.uscourts.nyed.53...
The actual taking of the bitcoin is merely taking custody of the bitcoin. The forfeiture process changes the actual _ownership_. Think in terms of when the feds take cash from a car. FIRST they actually take the cash THEN LATER they file the forfeiture.