en.wikipedia.org/wiki/Wu_Han_(historian)

Tsinghua University's archives give a more specific chronology for Wu Han's wartime appointments: after the full outbreak of the war in 1937, Wu Han went to Kunming to teach at Yunnan University, and from 1940 he moved to National Southwestern Associated University. Separately, the State Council's English site says NSAU was founded in 1938 in Kunming. So the article's sentence is incorrect as written: Wu did not join National Southwestern Associated University in 1937.

A more accurate summary would be that Wu went to Yunnan University in 1937, and later taught at National Southwestern Associated University after that institution had been established.

This mixes up Wu Han's 1959 newspaper essay with his later play.

People's Daily/Party-history sources identify the June 1959 article as 《海瑞骂皇帝》 ("Hai Rui Scolds the Emperor"), published under Wu Han's pen name Liu Mianzhi. A later People's Daily note from November 30, 1965 likewise refers back to the paper's earlier publication of Wu Han's 《海瑞骂皇帝》 on June 16, 1959. By contrast, 《海瑞罢官》 ("Hai Rui Dismissed from Office") was the later dramatic work/play that became central to the political controversy.

So the article's wording is incorrect: the June 1959 People's Daily essay was "Hai Rui Scolds the Emperor," not "Hai Rui Dismissed from Office."

This sentence overstates the situation. Some politically sensitive aspects of late-Ming/early-Qing history could indeed be censored under the Qing, but Ming history as a whole was not a taboo topic.

A Beijing Normal University article on the history of Ming studies states that in the late Ming and early Qing there were two concentrated periods of Ming-history research, and that in the first of these there was both the Qing court's officially compiled History of Ming (《明史》) and many privately written Ming histories such as Guoque, Zuiweilu, Mingshu, and Shikuishu. A standard reference entry on Mingshi likewise notes that it is the official dynastic history of the Ming, whose compilation was ordered by the Qing and completed in the Qing period.

So it is misleading to say simply that "the topic had been taboo under the Qing dynasty." A more accurate formulation would be that some topics or interpretations about the Ming-Qing transition were politically sensitive under Qing rule, not that Ming history itself was taboo.