When a coupon loaded with DOGE comes into offering people are going to go for the free money and eventually lose it on the casino. They are then going to go with buying DOGE and spending more DOGE on the casino - you might argue that I am contradicting my opinion about raising the value of DOGE by this but it is less significant that what celebs like Musk have already done. Gamblers being impulsive will spent bought coins immediately and therefore the casino will profit.
For some reason I only love playing dice at PrimeDice even though I bet for sports at stake but when I really feel like rolling dice and doing a session then I just deposit into Primedice because the betting is faster, I have felt and there is just a home feeling maybe because I have been on Primedice since their v2 I think.