A few updates that has been reflected on Wikipedia (but not here):
Rules regarding cruise and train tickets are added. The 24-hour provision now reads:
"Holders of confirmed onward air, cruise or train tickets for a max. transit time of 24 hours. Transit incl. multiple stops within China (People's Rep.), with a total transit time of max. 24 hours, is permitted. They must travel to a third country."
The 144-hour provision reads:
"NOTE 75232: This also applies to passengers traveling from/to Shanghai Port International Cruise Terminal, Shanghai Wusongkou International Cruise Terminal and Shanghai Railway Station."
For those who are unfamiliar with the train rule: when entering mainland China from Hong Kong on the Shanghai-Kowloon Through Train, immigration checks are done AFTER the passenger's arrival at Shanghai, only until then is the passenger considered to have arrived in mainland China. Those departing to Hong Kong from Shanghai also gets their immigration check done at Shanghai Rail Station, and they are considered to have left mainland China once they embark.
Also, Monaco and Belarus are added to the 72-144-hour TWOV list, however for some reason Monaco is not listed in Timatic (yet).