They aren't arguing that AAVE is another language entirely. They're arguing that it's a dialect of English. So not separate, then. Their point was that it's a lot easier to teach kids to read and write in Standard English if, at least initially, the teaching is done in AAVE. I think that you'll find consistency if you read more closely. For reference, Standard European Portuguese and Spanish usually aren't mutually intelligible, and are viewed as different languages. Different situation entirely. Portuguese and Galician might be a better comparison, maybe... But that's good for another conversation....But both list AAVE as a dialect of English. This is undoubtedly the right classification.
Journalists vied with each other to insist that AAVE should not be recognized as a language. What got lost was a much more reasonable and sensible point: AAVE as a dialect of English still deserves respect and acceptance.
From the article: This means that all dialects are separate languages, at least according to this article's knowledge of linguistics. I don't know if that's true or not, but they are definitely arguing that AAVE is a dialect of English and also stating that all dialects are separate languages with influences off of their base language.Linguists never say things like "This is just a dialect, not a language." Rather, they refer to one language as a dialect of another.
No, that's not what it means at all. They aren't arguing there in that section that all dialects are separate, they're saying that "dialect" and "language" are classificatory terms that aren't inherently judging. That's why they go on to explain how nationalism can influence that classification. You yourself could make the argument that all varieties of a language count as separate languages, but the article I posted does not.