Same here, I haven't encountered any casino posting names of winners in their platform. Even the person involved in scam accusation, the casino is very careful in releasing information just not to give any important information about the offender/victim's identity.
That casino should be sued and the victim should be given money for the damage.
So in such cases where the user is concerned about their info or is willing to put up a case against them they simply show their terms and conditions against it.
There are no written terms wherein the Casino is allowed to announce the winners of any of their games may it be big or small. As a matter of fact, they actually stated the data privacy law and how they should handle the player data privacy.