Interesting fact about that, those chapters are at different locations in the book depending on whether you are reading the original or the English translation.

In the original, they’re closer to the middle of the book, in the hope that they might evade the notice of censors. Whereas in the translation (at least into English), they were moved to the beginning.

I can’t remember where I read this, but I think it may have been an interview with either Liu Cixin or the translator Ken Liu in Clarkesworld.