Around 20 years ago we had a referendum to vote yes/no to become republic, cut tie with the commonwealth UK. Majority of the people of Australia wants to continue to be part of the commonwealth, so that was that. There are about 41 countries that are still part of the commonwealth - UK.
Many movies, reality tv, and documentaries on our tv here are from the USA. We have British too, but more from America. Not many Australia made movies/documentaries/reality. Right now our channel 10 which own by CBS is showing Steven Colbert late night show.