The NYT has always used the em dash.
This is a style article about it, from 2019, long before ChatGPT: https://www.nytimes.com/2019/08/14/style/em-dash-punctuation...
This is a style article about it, from 2019, long before ChatGPT: https://www.nytimes.com/2019/08/14/style/em-dash-punctuation...