Intellectual property will become even more of a problem in a post scarcity society. Those that hold the IP will not want to give it up just because it's value is no longer in the physical creation.
The music recording industry is effectively already becoming a post scarcity industry, and look how unwilling they are to give up their copyrights. Industries will cling on to things like rights to reproduce, rights to distribute etc. Don't expect these problems to go away because of some sci-fi future tech.
I don't think an AI Justin Bieber is that far off.
AIs can create pop music in your virtual world if you like that sort of thing. All the other AIs will be talking about it, so you won't need some central source of anything in order to have common ground with people in your reality.
It will be fine if random permutations lead to people in your virtual reality listening to "Yeah, Girl" instead of "Girl, Yeah" or "All Right Girl".
Movies won't be very important when you can interactively experience anything you want. Climb K2 but without the risk of permanent death. Movies will just be a Machinima subset of the interactive simulation if you still want them.
The music recording industry is effectively already becoming a post scarcity industry, and look how unwilling they are to give up their copyrights. Industries will cling on to things like rights to reproduce, rights to distribute etc. Don't expect these problems to go away because of some sci-fi future tech.