I agree with this and feel I've argued something similar.

Good examples are how Proust sells you on his book with his "Overture" and then when you start to worry about the diffuseness of what follows judged against the possible unenendingness of the whole work he throws in "Swann in Love" to prove he can (and will) plot and end. And how Shakespeare in the middle of Hamlet has Polonius reminisce about playing in Julius Caesar, a reminder to the audience: "Do not worry, I can totally write a tragedy - bear with me through this middle stuff, I'm doing a thing here."