I havent encountered or heard of for a casino to make out those kind of warnings but having those kind of cautions and reminders in text then i have seen one but this is mostly just that been rejected or ignored by most gamblers. Houses are really that mindful or really that in concern? I dont think so.
Maybe you didn't but such casinos do exist. Many of them offer different features to help gamblers stay safe.
Some of them offer what they call vaults in which you can lock part of your balance so you don't spend it for a period of time you set. Some others, for examples, will display a notification to let you know that you have been playing the same game for too long. Usually when you keep playing for more than an hour without taking a break.
You may think emplying such features is not good for their business but, in fact, it's the opposite.