Not exactly sure what you mean. Each coinjoin output is registered with a unique Tor identity, and the coordinator doesn't learn which inputs are associated with its creation thanks to zero knowledge proofs and other crypto magic. There's a (convoluted) metaphorical explainer for the protocol here: https://github.com/WalletWasabi/WabiSabi/blob/master/explainer.md

Don’t you have to know which addresses to send the CJ’d utxos to?

Jon_Hodl

Clients don't offer any data to coordinators, so there's nothing for a dishonest coordinator to dox them with. You can verify this yourself since all the code is open source :)

kruw

@kruw's bio

Hey, @kruw,

In relation to your CoinJoin coordinator, how do we know that you’re not doxxing every participant? 

How can we verify that you’re an honest actor?