Also, seems to me this "Manicheism" is no Manicheism at all, but a divergent Daoist or Buddhist sect that completely abandoned whatever actually Manichaean elements it had. Daoist and Buddhist deities are not Manichean figures at all, and the prophet Mani seems to have been as unknown as Jesus and Zoroaster throughout all of Chinese history, including the Chinese peasants who, however, probably revolted under a general religious impetus rather than a specific Manichean one.
It seems to me that Sinologists and Western historians in general are just trying to find whatever European influences they can in China and magnify them to the extreme. Apparently, it's not enough that Chinese Buddhism has to be the "Greco-Buddhism" adopted by Alexander's successors, that Greeks influenced or even built Qin's Terracotta Army, that the Islam carrying Greco-Roman civilisation with it had a massive influence in China, that Christians have been proselytising the Chinese since around the 7th century at least. They also have to add further European influence by saying Manicheism, a mixture of Christianity with Zoroastrianism (itself Europeanised thanks to Hellenism or, baring that, by being "Indo-European") played a crucial role in Chinese history.