no, hes saying that its about songwriting first and foremost for him, not just beats and rhymes. or rather, not moving from the subject matter of a song to those kinds of filler shifts you get in a lot of rap lyrics (eg the first two verses of i luv u vs the last verse). ie not beats and rhymes as separate entities. not sure how you jumped from that to the perspective that doesnt see rapping as being musical (or did you just create that to have something to argue about?). should say though that i think oddissee is a 'progressive' but the majority of rap is about disconnected writing (and i cant be positive that oddisee sticks to his method 100% either)
i do think rapping is musical, as a rhythmic element.
but for the most part, i dont care about the lyrics anymore. most raps are just chatting shit. entertaining for sure, some memorable lines (though this is often more musical, than textual), but when im listening to earl for instance, its more his facility with words that i like, how the words just slide against each other, and his tone, his voice, than anything hes really saying.
saying that, i was struck recently by how good the imagery on the takeover was, but again, its prob more just to do with the ice cold heartlessness, and that tone of disbelief and dismissiveness (as if hes saying 'how could you even think that you were better than me?') that jayz used to do so well.