That's the crucial point here
It is all idle talk until there is solid evidence that someone out there has actually wagered that much and is somehow unhappy about that. The whole story is so contrived and fishy with so much agenda insolently showing through and seeping out that it is surprising we are discussing it like it were for real. Anyway, isn't rakeback that something "extra" which you are supposed to get by gambling your ass off? But seriously, wouldn't it be too much of a good thing to ask for?
Actually it all depends on the site if they will give any extra rewards on their top wagered persons and for sure they know how to count the statistics since they all have the data's and look on it if those guys are deserving to get some bonus rewards for let say their millions $ wagered. but as far as what I see I don't believe that there's someone reach for million $ wagered since I don't see it yet or missed to see them up.
And if they reached for that figures for sure they are happy since they will never reach that million wagered if they are not satisfy to the site service,games or bonuses provided unto them.
They will play at places that already has stuff for them and they will come in agreeing to whatever is the rule here. Which is why many people questioned the authenticity of the claims since if they were real they would be very stupid thing to do as well. Which is why I believe what you will do is actually accept the terms before you play and know what you are getting into way before you even deposit let alone gamble that much money and this is why I think people will not really ask for something extra, only get happy if they happen to get it.