There is no other way around for them, is there?
Well... Assuming the Wasabi Wallet continues having a github repository, where the source code is there to check, compile and run yourself, no.
I was thinking, is it possible for them to somehow accept UTXO's for Coin Joins and then freeze them until your victim client provides further information?
No, because there's no information transferred other than your inputs.
I suppose there is no way unless Wasabi becomes a custodial wallet and starts requiring accounts?
Although, it's already pointless to use Wasabi, "upgrading" it to a custodial service would make it further pointless. So, I don't hold my breath.
This is scary.
It's noteworthy how important integrity is, for everything in life. In this case, for the development of a project.