If you are familiar with this American artiste you would know that he is a big time gambler or you can just say he is addicted. People are amazed he won such an amount of money in a single day but I'm not because there's a high chance that he has lost up to that amount or perhaps more than that if you calculate his losses combined.
Don't misunderstand his gambling activities. He considers it just entertainment and the amount of losses that have been bet is money that he can afford to lose. And the winnings he gets in a day are just a bonus from his pleasure when betting and he has another budget to have fun in gambling again.
This win might actually be a way to lure people into gambling, it's very possible that the casino allowed it to happen for promotion purposes. It could be a way of advertising their casino what do you think about that? It's just a random thought, It's also very possible that he just got lucky.
Do you think stake gave him the win intentionally? I think you have to see every time Drake gambles to know that Drake gambles purely using his own money and the win was purely obtained when he was lucky. He is indeed an ambassador for stake and does promotions, but that doesn't mean it happened intentionally.