I went to to 8 different schools between K to 12th grades in 6 different states, and I don't recall meeting anyone who was deadly allergic to anything. I'm pretty sure I didn't even learn about epipens until maybe later in high school or possibly college.

The only ailment in kids that I think I had heard of was asthma, for which people had inhalers.

Of course, my data is weak and anecdotal, but based on the fact that a staple American food isn't allowed in schools anymore, I assume something must have changed.

Attending K-12 in the late 80's/early 90's I didn't know anyone with a serious allergy in school. There was never any concern about peanut butter food/snacks, or anything like that. A few kids with inhalers, that was it.