I think it's a good idea.
Nowadays, many people encourage more people when they watch TV, and they seem to be interested in what they see.
If you can actually promote bitcoin on TV, I believe its price will increase by more than 10 times.
Advertisement in the internet is not always enough because not all the people are in the internet and there are some people who still just watch television for something like developments and the news about something so if we want to promote bitcoin then we should do it both in the internet and in television at the same time to get good results. I think there is no illegal in promoting in television so we will not have any problem.