Even if that were the case, which I'm skeptical of, you're missing the other side of the productivity question. One of the major shifts in acceptable language relates to inclusion, especially in regards to gender and race. Given open source's ongoing diversity problem [1], you have to reckon with all the labor lost from excluding people.

[1] e.g.: https://www.wired.com/2017/06/diversity-open-source-even-wor...