Hong Kong, Singapore, and overseas Chinese have a big impact on the Chinese content. Hong Kong even used to have a chapter (now it's a user group, for reporting compliance reasons)
I actually looked into this after writing the parent post, which was more of a frustrated quip and not grounded in data... Per this 6-years outdated page, in addition to Hong Kong, it seems Mainland China actually overtook Taiwan for edits in 2014, which is doubly surprising considering the ongoing ban and how Wikipedia could possibly tell the true origin if people use web proxies or VPNs.
