Network television shows would remain free, can't really charge for something that is available for free.
Cable shows that are currently shown on Hulu for free, no one should expect those to remain that way. Currently the only way to see that programming is to pay carrier fees via subscription. I subscribe to TV service, why should I subsidize service to others so they can enjoy content on Hulu?
What Hulu needs to do is link their content with the television providers so that subscribers can access their content for free. Non-subscribers could pay to access the premium content.