Nobody much considers "let a hundrend flowers bloom" (as a phrase) equivalent to the "final solution", not even in China. This includes people who know all about Mao, the cultural revolution, the power plays and the executions that happened at the time.
It's actually a stock phrase in journalism and writing in general in lots of European countries (I know that's the case of its use in at least 4 countries/languages).
This looks more like someone in the US, several times removed from the events (by ethnicity, nation, time, etc), delivering a paternalistic lecture on foreign history.
Examples of casual use in both US and UK:
http://www.economist.com/news/britain/21581984-inner-city-sc...
http://www.washingtonpost.com/archive/politics/1986/11/03/we...
http://www.theguardian.com/politics/2015/sep/16/national-ant...