If there is need for kyc especially for a suspected fraud then I don't see it as a problem but I'm really comfortable with a compulsory kyc as compulsion in all casinos.
For a casino to advertise no kyc and later make kyc a compulsion for withdrawal procedures is just not proper it's either kyc or no kyc
Take a look at your highlighted statement again and the first paragraph, don't you think that you are contradicting yourself?
Because most casinos always say that their casino is not a mandatory kyc casino, but kyc will be demanded if they suspect any fraudulent activity from your account, so it's just like saying one thing, but when they sense something fishy going on, kyc must be demanded for safety measures, that's what it is bro.