It's out of his doings and actions. If he will give advice to newbies, it's like what's the purpose of marketing a gambling site.
Gambling-related addictions and issues should only be shouldered by Stake. There's a Responsible Gambling noticed on the website on most newbies won't bother to read. There's also a self-exclusion policy and anything else.
Drake will just focus on what's written on the terms.
However, it's true that it breaks the purpose of the expensive deal with him that he should take a lot of customers through him and then speak with them. IMO, there's nothing wrong with that as the gambling sites are also giving a tip like that to their customers just as you've said.
I have to agree that Drake doesn't have a sole responsibility to give warnings to people about gambling addiction. It's not his role as a paid partner for a gambling site that he will market from now on. Although he can give warnings but not necessary. As always, the preventive measures to avoid the negative effect of gambling is thru ourselves.
The discipline has to start with the people as even though there are lots of advice and warnings, it still depends on the people if they will follow it. Every newbie should know and understand that prior entering the gambling scene.
Warnings are everywhere, but people tend to reject it as they already know it.