China never needed them.
The current crop of missionaries in China are fundamentalist Christians from the U.S. on a mission to carry the word to China. I have met at least a dozen at the handful of universities where I have taught. They do not identify themselves as missionaries to the university and their proselytizing is discrete, usually reserved for dinners at their apartments with targeted students. When the Universities find out are usually nonplussed, happy that they haven't hired the typical backpacker bedding students. EVERY husband wife teaching team that I have me in China have been missionaries. Granted, I have only met a few.

Occasionally the Communist Party leader at the school will do a purge; that happened at Hainan University a decade ago.