Guessing you mean in your post-2001 books, but this comment has me imagining a Black Mirror style thing where there's this future prediction in everyone's school books that all the teachers refuse to talk about.
Airport security is by far the most identifiable change for me personally. We never used to take shoes or belts off at airport security, we never walked through backscatter x-ray machines, we could carry liquids onto the plane and you could see your family or friends off at the departure gate even if you didn't have a boarding pass.
That's more media than school. But my understanding of it is that it kind of did. Mostly for people who frequent airports and Muslims than anyone else though