you a bitch
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.
What’s more, it’s been shown that copula deletion occurs in AAVE exactly in those contexts where copula contraction occurs in so-called “Standard American English.” That is, the basic sentence “You are great” can become “You’re great” in SAE and “You great” in AAVE, but “I know who you are” cannot become “I know who you’re” in SAE, and according to reports, neither can you get “I know who you” in AAVE.
In other words, AAVE is a set of grammatical rules just as complex and systematic as SAE, and the widespread belief that it is not is nothing more than yet another manifestation of deeply internalized racism.