this does not mean that it will always and everywhere be like this.
There will always be decentralized exchanges, which are superior in terms of enforcing arbitrary coin criteria, because they cannot be shut down. So you will always have the option to go and buy / sell this way.
Although it seems that some centralized exchanges even today will automatically block your deposit if the incoming bitcoin had traces of passing through the mixer in its history.
Great, so don't use a centralized exchange. You will never have your coins treated unequally in Bisq.