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.
Also, the principals involved in "disrupting" governments and existing financial institutions also face the problem of government reprisal. Liberty Reserve got seized and their principals arrested and charged with various financial crimes.
Say what you will about Bitcoin, it's been remarkably successful on this front and I'm not exactly sure how.