This phenomenon probably doesn't even exist.

it's not a studied thing it's just a casual observation people find funny, i'm a zoomer and it's usually super noticeable when I see a video of a millennial, your generation probably just doesn't notice it because you're so used to it. I did a test and millennial pause is literally the first suggestion that comes up searching "millennial" on tiktok. i'm a little surprised it's on wikipedia and not knowyourmeme or something tho