If you ask me how long will they continue without asking KYC to their customers, I do not have the right answer because that will depend on each casino. But the casino that wants to give the best services will still do this while they can also negotiate with the gambling providers not too strict to their customers.
If we talk about laundering money, we talk about a lot of money that will be used to gamble and for that, the casino can ask them about the funds, where the money comes from, etc. The casino can also ask them to verify those people to know their customers who use big money.
As for me, only small casinos may not use KYC. When they get a big money, they get a big responsibility for it. Even if we don`t talking about law problems, big casinos have a lot of controversial situations that can`t be solved without KYC. Blockchain is a good decision, but when you verified with your ID you have more arguments in some difficult situations.