Mixing sats (whether with a good coinjoin or a custodial mixer) never removes KYC.

KYC is the record of your trades associated with your IRL ID. That NEVER goes away regardless of what you do.

Mixing at most gives you *forward* looking privacy, i.e. it prevents someone from deterministically figure out how you spend your coins.

The only way for avoid a KYC record is by buying from different small counterparties while providing minimal info, e.g. a p2p exchange.