This isn't positive on short term (though it indicates some legality to bitcoins itself as it's sold as hold goods). Wondering who will be getting bitcoins (for most likely a cheaper price).
It is definitely positive on the long term. Here are the reasons:
1. The FBI won't be having the Bitcoin stash in their possession. Who knows? In future they might use it to destroy the crypto.
2. As you have mentioned, the legality awarded to the currency, as a result of the sale.