AS I noted, this seems to be the point that Richard Mitchell was getting at when he condemned the notion of Ebonics being a language.
Language is communication, but not all communication rises to the level of a language. Or so it is my impression. I claim no special knowledge of linguistics, but the thread seemed bogged down, and I felt like giving it a jump start.
My guess is that to be considered language, some sort of structure would be required (verbs, nouns, modifiers, etc. as well as rules for construction of sentences). I also suspect that it would need to embody abstract concepts e.g., names for numbers, instead of a sequence of grunts for the number, and names for things, instead of just pointing at the thing. Perhaps there are other requisites for a language.
Think of this as an hypothesis, not an assertion as fact.
Example of pre-linguistic activity: Responding to a rational argument by uttering "Slime!"
OK. I guess I can buy that. In terms of a "formal" language ebonics does not deserve a second look. It is not a language rather at most a dialect. It is not something upon which we need to spend any time, money, or effort.