It's worth noting that American censorship in, say, 1960, was at close to the same level. See: https://en.wikipedia.org/wiki/Film_censorship_in_the_United_...
Did the article imply somewhere that China is unique in it's censorship? I personally tire of this pattern: 1. Article submitted to an international forum about X country doing Y bad thing 2. "Well the USA is just as bad, they also did/doing/will do Y bad thing" Well yes, that is true, but people are voting up the submission because they found that X-doing-Y-today was interesting and don't care to rehash the history…
Jeesh - many reader of hn are in the US and if X interesting is happen elsewhere, they are reasonably interested that X is happening in the US. Also, many hn readers are India, they may describe X happening in India also. And notably, censorship in India is noted in a different post that seems properly to be getting attention as well.
And, of course, American censorship deserves mention because the USA has often presented as bastion of free speech. Just as much, something like a "feeling of freedom" is a big export of the US - in the sense that it's media products give people in more traditional societies that sensation. This was a big motivation of the original article after all.
Not all American media products are pro-American propaganda. Some are even anti-American. But the overlap/gray-area is significant and so the qualities of the USA aren't irrelevant to say the least.