The key thing to bear in mind is that everything that Chainanalysis says about transactions occurring is mostly based on their subjective interpretations and arbitrary assumptions, which means it often doesn't have a connection to reality, let alone legal validity. To be certain beyond reasonable doubt that a particular transaction is indeed coming from a mixer, they need to be involved in a mixing process directly, be a part of that transaction. The other transactions in which the blockchain analyst is not a direct participant cannot be viewed as illegal or coming from a particular service.
This is exactly how I would view it. For an exchange to confiscate your funds, there would have to be undeniable evidence for them to freeze them. As you said, unless you were a part of the transaction you would have no way of knowing this. This makes me wonder what analysis tools they use to obtain this proof.
I find the case about Binance freezing funds used in a Wasabi Wallet to be extremely bizzare. How were they able to know that this transaction took place on their platform.