Censorship in China is widely known and lamented. Chinese literature has a long history of what Emily Dickinson's poem alluded to: Tell all the Truth but tell it slant. It's possible that Mo Yan chooses "not to speak" about the political situation directly, but to tell it slant.
Even as Chinese dissidents like Nobel laureate Liu Xiaobo and artist Ai Weiwei suffer physical imprisonment, hundreds of millions of their fellow Chinese citizens are suffering a form of mental imprisonment thanks to their nation's system of internet censorship.
Since 2009, China has attempted to block dozens of sites that might harbor dissent. Recent visitors had told me to expect Internet restrictions. As a First Amendment researcher, I would see the access restrictions as a bit of a one-way street.