The terms of the casino won't allow the user to use it as a mixer. Because, casino doesn't allow the user to deposit and withdraw their coin without wagering the deposit 'X' times (X= 1, 2, 3, ...,10, ...). There is a high chance of losing small to big amount of the deposits during the wagering process. Moreover, the number of No-KYC casinos have decreased significantly. The regulations have increased widely in the crypto gambling industry. Even unlicensed casinos have the KYC and AML policy now to follow the local laws (to reduce the legal risks) of some countries.

However, it will be a mixer for sure if you see any new casinos with No-KYC rules advertising in Bitcointalk forum, (1) with the capability of processing large withdrawals, (2) without any wagering requirement.