Right, within it. As soon as you finish reading it, you immediately remember that world is not true. Immersion in a story does not equal lasting hypnosis. You can be immersed in a movie but you still know it’s fake.
What’s you point, here? That you should be lied to when you ask, or that it should refuse to tell you any kind of fiction?
I agree with your larger point that there will be ways to circumvent these systems, my only argument is that the lie/fictional story divide is a bad example because the line between them can be made clear with a single statement.