I don't think the author was saying Blacks speak AAVE at the exclusion of also learning American standard English.

There are plenty of English dialects and in dilects other languages as well. As long as people can code switch and not be trapped by speaking the dialect alone, what is there to be concerned about. It makes life more colorful.

https://www.ef.com/wwen/blog/language/british-dialects-you-need-to-know/