Just because dude intro's his rhyme with, "Coming straight outta compton" or says, "Living in Compton, California, C-A" on Dopeman doesn't mean dude is actually banging for the CPT. That was NWA's image and he ran with it. They also just repped South Central in general later in their careers, but Cube had left by then.
If it was such a big deal that he wasn't from Compton, it would have been a big deal back then. Oh, but it wasn't. He wasn't a banger, we all know that. Whoever had this question on their minds be pondering some trivial shit for reals.