Language learning is the entire remit. The Superpolyglotbros appear in our catalogue with Fundamental Spanish, an education and learning title, and the byline sets the expectation cleanly enough: this is a project about acquiring a language rather than a lesson dressed up as reading.
The approach is audible in the format. Sixteen hours and twenty-two minutes is a course, not an introduction, and the recording is delivered by the Superpolyglotbros themselves. Self-narration matters more in language teaching than almost anywhere else, because a learner is copying a voice, and the voice ought to be the one that designed the method.
What lies behind the name is not something we can document, and we would rather say less than guess.