I am pretty sure AML companies like Ciphertrace are able to track the movement of funds even if they use mixing services. They do live demos of their tech so it would be interesting to see it happen in real time
Not all mixers are equal. Simple tumbling methods were broken a long time ago, yes. A researcher
recently shared their work on de-anonymizing mixing services here on the forum. It's worth reading. The crux of it:
I found some trivial bugs (timing attacks, leakages, xss, ...) through which nearly all relevant centralized bitcoin mixing services could be broken. Based on outgoing mixing transactions (transactions sent by the mixer) I was able to identify the correct incoming transactions sent by customers (vice versa).
Of note, however, is the fact that he was unable to use these methods to break Chipmixer, whose tumbling methods can't be broken by timing attacks. I'm curious whether Ciphertrace could.