It's likely just something they came up with quite quickly. As others have said, he could even be improvising. That said, it is very nice and I could easily see it as an intro to a song, an interlude track, or even an Escapist-esque hidden track.
Don't trust genius. Anyone can edit it. I don't think it will be released in September if they release a single in May. They mostly release their albums about 2 months after first single release