Fly from Chiang Mai (Thailand) x Guangzhou x San Francisco x Miami - go and back. I need visa?

I find this on the China Southern Airlines:
Tips

For a passenger to enjoy the 72-hour free transit policy, the entry and the exit must happen at the same airport. For example, the policy does not apply to the following stopover flights:
Beijing–Phnom Penh (CZ323), Phnom Penh–Beijing (CZ324), Guangzhou–Moscow (CZ355, CZ6001), Moscow–Guangzhou (CZ356, CZ6002), Guangzhou–San Francisco (CZ659), San Francisco–Guangzhou (CZ660), Beijing–Istanbul (CZ679), and Istanbul–Beijing (CZ680)

Note: Please fully understand the free policy before traveling; the regulations of the Bureau of Exit and Entry Administration of China shall prevail.