The "Hundred Flowers" that Mei Chang refers to was a campaign in communist China that started in May of 1956. Also known as The Hundred Flowers Movement, the idea was initiated to promote greater freedom and thought of speech, even criticism of communist policies by noncommunist intellectuals, by lifting restrictions imposed on Chinese citizens. Mao Zedong began the campaign with "Let a hundred flowers bloom, and a hundred schools of thought contend."
The episode was leaked on April 28, 2017.