Oh that's a pretty much accepted history in China. You can't hide that because so many people witnessed it and so many of today's leadership in China were also victims of it. Xi Junping's own family suffered greatly during that era (Edit: Cultural Revolution, not Great Leap Forward, but one followed the other because Mao was trying to salvage his legacy after the first mistake).

State censorship isn't as simple as not talking about something. The cleverer way of doing it is to spin the truth. As they say in China, Mao is 70% correct and 30% wrong. That's how they spun it. Sure the Great Leap Forward and Cultural Revolutions were terrible but on the whole Mao was good. Then add in some story about liberation from the Japanese and the corrupt KMT and Mao's legacy survives.