For me, bitcoin being crashed or not won't impact those gamblers since I think that's even an advantage to them as they will have more Bitcoin in return if they will purchase it by cash. Since they are playing with Bitcoin currency on the gambling site, it means more bankroll to them that they can use in the long run.
When it comes to cashing out, if it was really necessary to do, whether the trend is uptrend or downtrend, these guys will convert their Bitcoin to whatever price.
Those are only for the gamblers that just came in after the dump but it's still a disadvantage for those who are playing before the dump came in because like you've said some of them will cash out when they really need the money.
You see more and more that casinos are switching to crypto payments. But then the anonymity of the crypto disappears a bit, because large sites that have been in the business for a long time will start with the KYC. You have to weigh the advantages against the disadvantages.
That's somewhat true but it still depends because even though some of the popular casinos start accepting crypto deposits they'd still convert those deposits to fiat value some examples that come into mind are Rollbit, Roobet, and Duelbits. For the KYC, it varies from casinos though some of them would only be optional then there are others that require a bit of KYC like Roobet.