That clip doesn't prove anything that is relevant to this discussion. You're making assumptions, and that is a mistake.
So, americans do not learn about the reichstag (lol!?). Your argument is that because the average american does not know what the reichstag is, the movie could not possibly represent it.
This is a contradiction to everything else in this topic. Everyone agrees this scene was based on Triumph of the Will (Triumph des willens). Which was a nazi prpaganda movie, released in germany, in german, was never translated. The film is quite unknown in Germany's neighboring countries let alone a country 5000 miles overseas.
Triumph of the will is even less of a household name than the reichstag. If your argument were true the scene could not be representing hitler in some way, let alone TOTW. We all know that is not true.
Besides, what school teaches about WWII, but not the capture if the reichstag, which was one of the most important achievements in the fall of the reich? Probably because the Russians did it. And we all need to know them Russian commies are bad, bad bad!