It may have been, it's relatively common for something like this to be included in coverage of Vietnam and the cold war. Current events related blocks are also often put in social studies curriculum and propaganda is a often a suggested tie-in.

While your teacher sounds like they went above and beyond, they probably weren't working against the system. And that's coming from a burned out ex-teacher. We have issues in our schools but for the most part curriculum designers are trying to help. For every terrible Florida-like headline depicting a leap backwards there are many steps forward taken under the radar