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.
That a casino asks you to do a KYC verification doesn't mean they are going to treat you better or give you any priority than those other registered customers that have not passed KYC. The KYC is just to verify their customers identities so that if there is any ugly situation, they can easily phish out the user who committed such an ugly incident.
Casino are aware that so many people hate KYC and therefore if government doesn't deemed it necessary for them to do KYC, they might remove the KYCs option but do you think government will ask casinos to stop KYC? The answer is no!
The government is very concerned about money laundering cases, and if, by mistake, someone wants to clean up tainted money through the casino, the government will get the person's details through their KYC information from that casino.