I think the point is it's not going to suddenly give us surprises like Banksy shredding art.
These AI’s are literally trained on all of human creativity… i struggle to see how there’s any indication AI would fail to be as creative as a human in even the near-ish future.
However, you fail to recognize that OpenAI also created Whisper, which is a quote capable speech-to-text transcriber; and this tool easily converts audio and video (those verbal bits you mentioned) into text.
So the pool of creativity which OpenAI can train its models on is far larger than just original text; further, they demoed image modality a couple weeks back which would allow for VISUAL creative works to be parsed as well.
Do you mean things like tone, facial expression, the general “energy” around a conversation, etc?
Basically, pick a random human from the street and they would be talking and listening a lot more than they would be writing. Those talking and listening is never going to be captured by any digital system.
It might end up that written text has enough similarity with verbal communication that it doesn't matter anyway. But that's hard to guess as a priori that it would be the case.
And the future is now, of course, because there are tons of such artists and the value comes only from the elite who ascribe value and not some inherent value of the thing itself. Things are important ("worth money") because tasteless fucks with money say they are worth money. Go watch "The Menu". Ralph Fiennes face cooking the last meal says it all.