It’s called copula deletion, or zero copula. Many languages and dialects, including Ancient Greek and Russian, delete the copula (the verb to be) when the context is obvious.

So an utterance like “you a bitch” in AAVE is not an example of a misused you, but an example of a sentence that deletes the copular verb (are), which is a perfectly valid thing to do in that dialect, just as deleting an /r/ after a vowel is a perfectly valid thing to do in an upper-class British dialect.