How casinos would keep high rollers and manage their streamers or their sponsored ambassadors, if odds providers were doing this kind of thing on their own? I think it's just an excuse from the customer support to avoid complaints from players and getting a bad reputation too quickly.
I don't think it's an excuse only, every betting site has a team who is working with the odds provider. They are working to find out this type of users who is following some tipsters and winning all of his bets. Odds provider has an important role to find out these things. And the betting site team reduce the max bet limit of those questionable users. Perhaps, you will get the same answer from every betting sites for such issues.
Nothing is really special on this birthday not like what we imagined

By the way this week I claimed $9.5 weekly bonuses from $9k wagered
Yep, Stake celebrated the previous birthday with a lot of bonuses. There was bonus drop for almost a week. They ran especial wagering contest, raffle draw, pre-monthly bonus, monthly bonus etc. But we got monthly bonus only in this time, and few bonus drops on Stake birthday date. However, they are running $5 million wagering contest, which is the biggest one I have ever seen in any crypto casino.