I'm not saying it's fighting money laundering, it's just that casinos are always vigilant in that case and we do know that online casinos are not the best destination, but who knows if someone is doing that in one of the casinos?
It is indeed very rare that someone gambles using money laundered from money laundering but casino vigilance is always at the forefront for the future of the casino itself.
If that happens, of course, casinos will be threatened with closing by certain countries because of accusations such as covering up evil acts of money laundering in their casinos.
From this case the casino imposed KYC on every customer who deposited large funds at one of the casinos to verify the source of customer funds.
The criminal who want to laundry his money isn't have any intention to gamble on the casino, but he just want to meet the minimum wagering amount in order to withdraw without get flagged by the system.
KYC isn't the best solution to fight money laundering, but it's add another barrier in order the criminal will be harder to escape and hide his identity. The only way the casino to fight money laundering is confiscate the funds and terminate the account without anyway to recover it, but most people will call the casino is scam.