Lets have a look on this situation from following point of view. Some persons who gamble, search emotions, such as feeling of a risk, joy of victory for example. When person becomes rich, he starts to care little about the money he could won. He stops getting excitement from a risk if he would lose not everything or not. Those who suddenly became rich might loose taste of enjoyment from gambling. Such people imho would stop gambling if not at all, then for a very long period. However, those who are chronicle gamblers, I think they would spend all of their wealth on things they dreamed they would buy if they win. Which means they wont have money anymore for gambling.
Have you also considered those that are already made while gambling they have money already and are just gambling for fun so even though they win any big amount do you still think they would stop gambling? well, to me I don't see any reason for such person(s) to stop gambling so soon because he is already self made and is just playing for fun and to catch cruise while the days and if he wins then fine but if he lose he don't care about it because they always gambles with what they can afford to lose.
Those who have already made a fortune and continue gambling, they do it without a sparkle in their eyes. They do it, like you have said, for fun, for a process. However, whenever they find something else or new that will switch to it quickly. I dont try to say that those who became rich from gambling stop gambling immediately and at all, but they do it in a really rare case or on special occasions.
You know, it is hard to discuss such thing, when none of use yet became really rich. I will speak for myself. Even though I gamble for fun from time to time, at the moment when I become rich, gambling will be one of the last things I would think about, because I would not have time for that, as for me, there is still so many things I have tried, seen, discovered, visited.