Behind the scenes
The literal translation of the Chinese term for President of the PRC is 中华人民共和国主席: Chairman of the People's Republic of China (technically, Chairperson). Fallout 3 explicitly names Chairman Cheng as holding this post. Given that the GNN transcript is notorious for the amount of outright errors contained within, this is a deliberate retcon. Xin never existed insofar the series is concerned.
Xin is mentioned only in Fallout 2.