You can call me regressive but I am against teaching kids things who are not really supposed to do because giving the information may tempt them to try it cause that's the age when we want to try anything that gives thrill but they are not really ready to consume such things but can touch the basics of addictions that cover the wide range including smoking,porn, alcohol and as well as gambling too other than that telling them you should not do might go the opposite way.
There is an age that a child will reach in life where, even if you don't teach them about a particular thing, they will either come across it in one way or another, either through social interaction with friends or on the internet. They will definitely have to learn about it.
You can't just walk up to 6-7 years old and start telling them about gambling or other activities you either want them to stay away from or learn how to handle; it's at least from their adolescent stage where you know their mind is prepared for what you are going to educate them about.
I personally don't see anything wrong with teaching a child about the things they need to know before they learn them by themselves.