It just happens. I think it originates from when Athlons used Phenom Deneb core dies when the Athlon ii/ Phenom ii series originally came out. When you unlocked an Athlon tri core for instance you could have possibly had a full blown deneb Phenom ii core with L3. But now the Athlons have their own bespoke core without L3, but the naming system must have stayed the same I suppose
Ah! That makes sense. I totally forgot that Athlon IIs started life as crippled Phenom IIs.