Always remember, casinos are not your friends, they only exist to make money and any promotions or freebies are only
there to keep you depositing, if they think they can increase the income by quietly dropping rtp,s , they will do it.
To be realistic, they are no worse than many businesses, car dealers,estate agents,insurance brokers (you dont need to do anything
to renew, just hope you dont notice the extra increase in premium we are not pointing out to you).
All you can do is be aware of the rtp,s of games you play and if they keep making adjustments (downwards) drop them and go elsewhere.
One of the worst cases of dropping by stealth has been at Videoslots, I bailed out when everything changed after they got sanctioned.
When I first joined, every game was on top rtp and all they were all listed in the rtp history, suddenly they dropped rtp,s on providers
which allowed variable settings and buried the fact in a small daily news section, also the target rtps were no longer listed in the history.