The author reserves the rights anyway. Currently has it released to the world as stated in the license guide. But the author can change it or retract it any time. Rights can be reserved when specific licenses are set. If you notice, there is nothing on the license that states that the author cannot take back the license, hens, the rights are reserved.
Of course it can also mean that the author just copied the phrase.
Also, if you want to do serious work, don’t base your assumptions on a page on the internet. Maybe someone just copied the song and licensed it without anyone noticing. Better contact the author and ask for his permission. Better safe than sorry.