The first thing I thought of reading this was how you could write the exact same about the rural midwest US. I was the only kid in my class who had ever seen a black person face to face, and that was because I lived in Florida first. My grandma still calls to warn us to stay inside if a non-white person is spotted near town (usually a utilities guy fixing power lines). They just have no experience with the wider world and know only the stereotypes they echo back and forth to each other.
The peace corp warning does a good job framing it as it is, but it's important to remember that "innocent" ignorance can still carry real violence and hatred.