Are you saying we should reserve the term "ASCII art" literally for text containing just the original 95 printable characters? Even if you can make a good argument for that, I fear you're fighting a losing battle.

Yes, the terms ANSI art and Unicode art have been around for decades and are defined standards as well. No need to make an argument.

Neither a superset or subset of a thing is the thing. Only the thing is the thing.

But when you combine units of language the result is not just the sum of the parts. word1 means X and word2 means Y but established phrase "word1 word2" rarely means X + Y. The result relates to X and Y but it has a life of its own that depends on how it's used.

Think of these and how they are more than sum of their parts. Demo scene. Serverless. Skyscraper. Information security. Artificial intelligence. Drawing board.