It is not hidden, but maybe they did not announced publicly. As we all can see here
https://help.stake.com/en/articles/4821738-what-is-rakeback-how-it-works-and-how-to-get-it and as confirmed by live support, the rakeback is now 5% only. The same information is also available under the VIP club page, but the information about when it is changed is available in the help center page. The article about rakeback is updated this week. Anyway, I dont understand why Stake cut it 50% off, but I think it may affect some players and may leave Stake because of this change.
Don't know what to say now, but it is a tricky move from Stake team. And they have done it really bad. The rakeback was 10% since the beginning. Suddenly they have reduced the rakeback rate by 50% without informing the users. At the same time they have increased the weekly bonus amount by 50% (up to) and announced it on the telegram VIP channel. Basically, they aren't giving anything extra. This change will bring benefits for Stake actually. The rakeback amount was promised one for every VIP user, but there is no guarantee that everyone will receive 50% extra on the weekly bonus amount.
It could happen, there could be some giving free stuff that change time to time, we just need to understand it and accept it and move on. I get that it could be upsetting, but casinos needs to realize they are there for profit making, and the best option they will have is the way they will go.
So, if dropping one thing 50%, and increasing another 50% gives them a better return, then it would definitely be the path for them, why not pick the most profitable thing? They probably calculate how many people would leave if they do such a thing, and realized that it wouldn't be really that much of importance, and went with it, and we as gamblers need to accept that.