Wasabi Wallet devs wouldn't have hired chainalysis company if they themselves had technical capabilities to analyze every incoming transaction and make decisions based on such analysis. Imagine you have a bunch of institutional clients who want their transactions mixed as quickly as possible. They share their inputs with you for mixing, but instead of providing the services you are being generously paid for, you waste everyone's time trying to figure out which of the inputs came from criminals. Isn't it better and more effective to find someone who already has a full database of criminals and who can share this data with you in exchange for a small fee? This surveillance firm has a final say since Wasabi Wallet has no other data to rely on except for that provided by that firm. In other words, if chainalysis say that a particular transaction is of high risk, Wasabi Wallet accepts that as undeniable truth blacklisting the transaction.