Cult scripts are screenplays in Movie Business based on real films and data about them from IMDB website. They were introduced to add some flavore and immersion. It was not intended to be available for purchase for players. One player suggested the idea that you could buy an iconic scenario. Although I'm not sure if this is a good idea, this possibility will appear in the next version of the game.
The cult scripts in the 2020 edition will appear on the script market, where the player will be able to buy them (these will not be all such scripts but only those that will not be taken by computer players). These scenarios will be specially marked (highlighted) and their author will be IMDB. Of course, the price of such scenarios will be much higher than other scenarios available in the game.
Why it doesn't have to be the best idea
I will admit that I am not convinced of the complete legitimacy of this idea, and it is from the simple fact that I am afraid that players instead of creatively approaching the making of films and producing them based on their own ideas will focus on "hunting" movies known to everyone. I remind you that the production of films based on cult scenarios is expensive, and the effect does not always have to be in line with the expectations of the player (ie, such a movie can gain much worse ratings than in reality or much weaker profits).
That's why I allow this feature to disappear from the game in the future, but i'll take a chance and wait for your reactions.