It may not invalidate, but it puts them into perspective. Most of his rant seems to be about how in Khan's quick summary of WW2, the UHmericans aren't portrayed as the morally superior righteous warriors / soldiers that defeated the evil Hitler and stopped his wrongdoings. And the Bolsheviks shouldn't have been mentioned without the required nuances that would teach present-day students that communism is evil. Or maybe I'm just speculating, but that's how it got to me.
I think it's more complex than that; in his point of view, History of WWII shouldn't be taught this way, in large (huge?) brush strokes. He argues (IMO successfully) that you must go deeper in details to get at least a basic grasp of these important events, and give them some meaning.
Said differently, a simple list of loosely related facts simply doesn't constitute history; and to make the narrative compelling, understandable and memorable, you have to give at least one (and preferably several) explanation for the facts, else it's only kindergarten stories, not college-level material.
Now I didn't see this particular video; maybe it's just a quick overview of what's to come in a long list of upcoming courses.
The history section is sketchy and just a beginning. Instead of latching onto the fringe of the Academy, History (perhaps because the math was beyond him), the author might have constructively suggested how to beef it up, present multiple views, talk about morals vs perspective.
Instead he chose to bash a popular figure. Probably because it gets hits on his blog, but who knows, I'm cynical.
