To expect a sexual provider to disclose all his ETSs is a pointless and unrealistic expectation. What is the intention? To protect the clients? If a provider does not care about the clients, healthy or not, he would not tell the true. It is not only an unrealistic expectation, but also one that violates privacy rights. It is also concentrating all the weight of the responsibility on the provider, when each one of you should be responsible for taking whatever precautions are reasonable for you.
Let's try to focus the conversation on what we can do to keep ourselves protected, instead o what others should do to protect us.