Attackers dust addresses that have previously spent a utxo, not ones that currently control a utxo. So, now there is a new utxo at that address, and when the wallet goes to spend it will use the new dust utxo along with utxos at other addresses the wallet controls. Now this new spend tx reveals on chain that the previously used address is connected to other addresses.
That seems to be the claim by the author of Libbitcoin. You would expect much faster sync time from Bitcoin Core too. It is limited by CPU signature validation.