What specific abused you consider for requiring KYC? There’s a lot of user here encountering problem on a Casino by simply using an arbitrage betting.
I still doesn’t fully read your ToS but it’s important to have this info(assuming you didn’t right this part) since user will automatically assume that your casino will never ask KYC no matter what will happened on their account.
Different forms of fraud perhaps like bonus abuse, multi accounting, ban evasion. They could put that in place to ensure that it's one person per flagged account. The ALM have an AML policy under their terms, so it's safe to say they could go to greater length to verify their customers in the accounts get flagged or if there are some suspicious transactions.