Data breach doesn't necessarily mean your IP address alone, it includes your KYC documents or any other data you provided for the cryptocurrency casino to get verified. But there is no difference with fiat and crypto online casino in this situation and moreover Fiat casino mean you also added bank details which is highly sensitive than IP or your name.
But you don't need to worry, the cryptocurrency casinos have high security standards and I don't remember much of data breach on a casino than centralized exchanges.
I guess only a few online casinos are really secure and insured in case of a data breach and hack. Also, much better to use VPN that has TOR on it since I think it will surely hide the IP address and cannot be tracked down.