Well, I really do not see anything wrong in withdrawing funds from a casino directly to an exchange, and this does not matter what type or which exchange, as a matter of fact, I've withdrawn funds from different casinos and sent directly to exchanges like Binance, bybit, kucoin and several others and I've never had any issues receiving the funds.
I think we all have to understand that casinos are also legitimate businesses just same way exchanges are, so it's completely wrong for any exchange to flag deposits from casino as illegitimate, except there are other issues the exchange has with the casino where the funds is coming from and decide on their own to flag payments coming from the casino.
I think users should read the ToS of exchanges and, based on that, decide whether to make a deposit from a gambling platform or not. For example, Binance states in its ToS that users can't use its services for gambling activities, sports betting, and other similar things, while Bybit doesn't mention gambling in its ToS at all.
Generally, it's worth noting that the ToS of some exchanges are very similar and look like they use the same template. Frankly, it's unclear what they mean by “ participate in gambling activity.” At least it's strange that Binance forbids it in its ToS but, at the same time, continues to keep the FUN token on its platform, which exactly can be used for gambling activity. For example, on the Freebitcoin site.