Why would you even talk about it if you know nothing about it? I believe that's a problem for people who don't know what they are discussing. They push themselves to let others see that they are knowledgeable about something, but when it comes to application, they don't know what they are doing.
It's like researching and not knowing what to do with the knowledge. I think it's important to have that firsthand experience if you advise someone, but if you are just going to talk about it, I think it's okay. It would depend on how the conversation goes, like if they are going to be talking because that person is interested in learning.
The important thing at the end of the day is that people understand the positioning that they have, whether it's about experience or not, that gambling can be addicting and it needs to be controlled.