It’s the same as Germany. They have rules and processes setup to deal with confiscated assets. They can’t just decide to keep something if it may go up in value. I imagine it would easier to auction the BTC no matter what and try to pass a bill to begin buying BTC then it would be to just move the confiscated BTC into a reserve fund. Especially when you consider that a lot of that BTC was stolen from actual victims who probably want to fight to get it back (see: Razzlekhan).