Casinos existed without the need for KYC's until the government made it a requirement, and they started demanding it. IMO If the government no longer requires casinos to do KYC verification for new gamblers, casinos will go ahead and still do KYC verifications because they have seen the benefits of knowing their customers better than when they just allowed people to come onto their platform and gamble without their knowledge of who they were. What do you think? Do you think some casino's will revert back to non-KYC and allow money launderers, plus other fraudulent people have their easy way with them as a way to attract customers, or since they recognize the personal benefits of KYC to their casino, will continue demanding it even if it affects their customers?
The truth is that most people tend to love Casinos that has enable KYC because it is believed that those casinos have a good security measures to keep gamblers data private unlike most of the Non KYC Casinos that allows any kind of people to open account with them without actually no the kind of person they are, though I'm not saying that all the Non KYC Casinos doesn't have a good security measures but I don't think we can compare those Non KYC to a KYC casinos in terms of users privacy.
However even if the government changed there mind to allow casinos decide if they should stop or continues the use of KYC on there platform I believe that those Casinos will still keep using KYC because is actually the best way to no there customers and also to prevent unauthorized access from a third party were as if the platform noticed a strange attempt of login from unknown source they will require facial verification to be sure if truly is the person. But however if the KYC is not enabled on a casinos they hardly dictate if is the third party or not.