They will create not just words and images but sets of rules like computer programs. But in order to do this with ease, there will have to be authoring environments that are easier to use than programming languages, authoring environments that allow creators to focus more on content and less on computerese, that let them preview the many possibilities inherent in an interactive story. Like any writer, the student's main focus is on characterization and dramatic effect, and have to be artistically creative in coaxing the interactor into saying the things that will make their characters come to life. But the appearance of a new medium does not mean the old ones disappear. Dramatic literature did not end when the novel appeared.
Folk ballads are still popular despite the invention of the television or the symphony orchestra.
A new medium of expression expands the repertoire of ways in which we can think about our lives. It does not eradicate the previous media if we still have things that we need to capture in those long familiar, ever-evolving forms. The storytellers of the future will just have more ways of doing what they have always done. When binge reading was relatively new to the world, Don Quixote went mad from spending so much time in the fantasy world of the chivalric romances. Most of us, however, can tell the difference between a jousting knight and a windmill.