Agree on all counts. See the large difference between the nominal air temperature, and the WBGT (which the chart above is based on). 100F is totally fine (athletically) if the humidity is relatively low (less than ~30%), it only gets bad in combination with high humidity (and practically, with a lack of wind/shade, etc.).
As an example, where I am currently, it is 95F with 37% humidity, which is just under 75F WBGT; green and fine for athletic activity. It's hot for sure, but not even into the yellow range, even though the school has cancelled PE, etc.
No issue with parents being extra cautious, of course, but I wouldn't have a problem with my kid playing games in the current weather, personally (and our games this weekend are still on, as of this moment). Based on the science and weather forecasts, it shouldn't be an issue medically, at least for the kids.