You could equally say "Speech, but without US government oversight, is exactly what the pedophiles and terrorists want to have".
I'm honestly not even worried that Facebook is going to flout AML laws. I'm more worried that they'll use the fact that they're using newfangled technology and the political and economic weight of their crypto consortium to get favorable legislation passed. And then, because of said crypto features, we'll end up undermining laws that fight money laundering and other financial crimes.