As an early 90’s millennial, I’ve never noticed a “gen z stare” as described in news articles like a “blank face that shows lack of social skill or ability to think”. The only times I’ve witnessed it happen and seen the older person accuse them of “gen z stare” is when the older person says something off hand or dumb but isn’t self aware enough to realize they’re being weird. Hell, I’ve given people a blank face countless times because I was taught it was better to say nothing at all sometimes. Especially when it came to talking to older people at work.
I remember when I was 16, some middle aged guy at work accused me of having no personality. In reality, I kept all conversations short as possible with him (like almost everyone in the store) because they were casually racist and misogynistic.
It’s quite possible you’ve done it tho.im 41 and never thought about it until I heard about it. My CPU usually resets and just plays jenny talking to Forrest Gump on the bus. “Are you stupid or somethin?” And then I come back to reality and can function again, and respond in a manner that isn’t offensive. If my brain didn’t reset, it would respond with low RAM and i would invariably say something incredibly offensive.