That was an interesting essay. The writer does seem to give "credit" for the spread of the English language to the Americans and I find that kind of odd.
Anyway... I don't know why we think right now that American influence will last longer than any previous "most powerful ________ in the history of the world". It's a pretty short lived "superpower" right now compared to the ones that came before it. Maybe it'll last forever, but I doubt it.
On the subject of Disney... they are children's movies. The actual stories that came before the movies will be around forever, the movies won't.