Was doing some research and notice something.
Xbox codenames usually utilize a theme such as places or people/animal names.
Playstation codenames are themed around Shakespeare and the Pro versions around The Matrix.
I was beginning to think it may just be an AMD APU just like Strix Halo.
But then I remembered Playstation also used Latin names such as Orbis (Circle) for the PS4 Dev kit and the PS Vita (Life).
Following that, Magnus means (Great) in Latin. Which could be a Devkit codename and not necessarily the codename for the APU.
Shakespeare also talks about great in one of his lines.
Shakespeare
Twelfth Night (Act 2, Scene 5):
"Be not afraid of greatness: some are born great, some achieve greatness, and some have greatness thrust upon 'em."
All this doesn't mean it's Playstation related though.