Since they’re vernacular you’ll mostly hear them being spoken, they aren’t really written
AAVE is commonly “written” now because most writing is texts and social media comments. So even if they luck out and learn “proper” English, people still going to type on their phones the same way they talk.
Even for white kids, most of Gen Z slang is just taken from AAVE, when older people complaining about not being able to read zoomer slang from text or comments, it’s just heavily influenced by AAVE.
There’s been bleed over for centuries, but with the Internet and social media it’s merging faster, which is common for dialects of people that interact frequently