KYC approval is usually reserved for high ranking officials. Those who are trusted on the site they will be responsible for KYC data. If there is any kind of KYC related complaint on any site then the responsibility falls on the persons in charge. But even in this KYC of many organizations can be stolen. But naturally there are no such problems in all good casinos or gambling platforms. The owners of the casino or gambling platform generally keep a good investigation on this matter otherwise the casino will not be able to gain a good reputation. KYC has both positive and negative aspects but considering all the positive aspects are more visible.
I'm beginning to think that this call for KYC awareness in casinos is being overrated, (I'm not saying we shouldn't take precautions though) if you listen to those who are complaining or have ever complained about their identity being exposed after they Completed KYC verification for a certain online service it has never been linked to a casino.
It's either from an exchange or any other money managing company, I guess hackers don't really focus on gamblers not sure why tho, but we should still keep our guard up and keep on with going with the best practice by choosing a reputable casino or perhaps looking for a no KYC casino.