No, if that was the author's intention, he would've simply pointed out that "unicode" was renamed to "str", while "str" was renamed to "bytes" and is no longer

No, if that was the author's intention, he would've simply pointed out that "unicode" was renamed to "str", while "str" was renamed to "bytes" and is no longer considered a string. Instead, he wanted to demonstrate how Python 3 string handling is some sort of a major breakthrough when it's largely a cosmetic change.