This is fucking BULLSHIT.
As OP said: Typical behavior of ALL this casinos.
When user is LOSING THOUSANDS it's = SUPER FINE
and no KYC is triggered, or anything, but if we HUSTLE them and WIN BIG at some point then they come with ALL SORTS of fucking bullshits to PAY OUR FUCKING MONEY $.
Typical behavior of ALL THIS CASINOS this days.
They are just a bunch of nasty scammers, nothing else.
The bullshit you're referring to, is a clause on their ToS saying large and abnormal winnings are subjected to investigation. If there's nothing wrong and the players play fair, the funds will very likely be released.
The typical behavior you're referring to, is an attempt by casinos to balance customer's privacy and govt. intervention. They only ask for KYC when situation requires because they won't scare people by KYC when not necessary, while KYC is one of the things required for legal compliance.
The bunch of nasty scammers you're referring to, is OP being impatient with the process. He literally only need to wait, and once processed and passed, he didn't bother clarifying things.