From my understanding, the actual syntax of Southern dialect hasn't changed fundamentally over the last 200 years while Ebonics is mostly patchwork where new euphemisms and "rules" are always cannibalizing the old ones.
I think it's not far from the truth - Southern American English is like a branch of a more archaic form; I'd go as far as to say that sometimes it may even sound almost British, mainly because of it's abundancy of dipthongs.
Ebonics doesn't really have rules, from what I observed - people try to make up "rules", as if to "teach" it to someone later, but it's not substantial. Being almost entirely comprised of euphemisms is a common trait of lower class dialects overall. It also easily bleeds into criminality - the infamous Russian "Fenya" dialect of the Odessite bandits is a great example of a dialect essentially coding what the people speaking it are conveying. A similar thing happens in Ebonics.
Ebonics doesn't really have rules, from what I observed - people try to make up "rules", as if to "teach" it to someone later, but it's not substantial.
This whole push for higher education to recognize and study ebonics as if it were a real language is just a desperate bid to avoid the very obvious truth that niggers (and anyone who uses niggerspeak) are retarded and lack the mental capacity to speak English or any other language properly. It's just graduates from grievance study programs trying to spin their retardation as some 200IQ move where they're actually so smart and great and creative that they created a whole new language that's so much better and more soulful than English, and if you refuse to acknowledge that then you're just an uneducated stupid white chud. It's the sjw equivalent of an elementary schooler losing some random recess game and making up a new rule that explain how actually they won and you just don't understand the game, basically.
I remember back in the day it was a huge faux pas to refer to a black person as "articulate" or "well-spoken" since it implies that most niggers by default are not articulate or well-spoken (which is true, but we have to pretend not to acknowledge that.) This seems like the natural evolution of that, where we have to pretend that some ambiguously-sentient ape mumbling about muh dih or finna fuh a hoe is just as worthy of respect as literature or a speech written by someone with a strong command of the English language who carefully chooses every word and syntactical choice to best convey the point they're trying to make.
