I think they may confused because 1) the specific phrase "diversity, equity, inclusion" and term "DEI" only really started to be common around 2019-2020, and 2)

I think they may confused because 1) the specific phrase "diversity, equity, inclusion" and term "DEI" only really started to be common around 2019-2020, and 2) DEI only really entered the public discourse in the past couple years. This is causing people who were not that aware of these topics before to jump to the incorrect conclusion that because they weren't seeing discussion of "DEI" before that period, corporate diversity programs in general must be recent, whereas in reality it's only this specific name for them that is recent.