He has a partnership with Stake.com and I assume the majority of losing bets are bankrolled/credited by Stake in exchange for free marketing.
Are you trying to say that stake.com are the ones losing?
However even when he has partnership with stake doesn't mean all the money he's gambling with are funded by stake.com, gamble with free money makes no sense because it looks like you aren't gambling at all because you aren't gambling with your money. If you want to talk about real gambler you have to make mention of gamblers that uses their own money to gamble, which means the person is a real gambler, but drake is a definition of a real gambler.
Yep, as the brand ambassador of stake, Drake definitely gets some money from it and Im sure there is a special deposit bonus for every time he plays.
So he still gambles using his own money, not the free balance from stake. Celebrity like Drake definitely wont gamble with fake balances/monopoly money even if its just for marketing.