Earlier quoted context omitted.
ASCII means more than just characters from the ASCII character standard today, for better or worse. The "modern" translation would be something like "text". I don't agree or disagree with it, so don't argue with me, just trying to explain how people use it today.
Anyone can write that a word no longer has its defined meaning. That can’t even be refuted, as it’s certain someone is confused somewhere. However, ASCII is not a random ancient word, it’s a ratified standard. Would be like calling any datetime format “ISO8601”.
The concept of an extended ASCII encoding goes way back: https://en.wikipedia.org/wiki/Extended_ASCII, and UTF-8 is just another extended ASCII encoding, albeit a very clever one, with a lot of codepoints.