Meaning whenever the hell they feel like it. From the outside looking in, one problem seems to be a lack of a legitimate legal framework. Is there truly law in China? In the US at least, companies can throw out illegitimate requests for information. Can you tell the Chinese government, "no" for any reason? Citizens in western Democracies regularly sue their own government and win.
This, "everyone does it" defense is bullshit.
e.g. 'For that reason, the Chinese Cybersecurity Bureau does not plan to politely make a formal request for the information. The fundamental premise of the new cybersecurity systems is that the government will use its control of communications to simply take the information without discussing the matter with the user.'
Does the author have some magical view into the Chinese Cybersecurity Bureau? Is he making this broad statement based upon something that the CSB has said? Or is it just his viewpoint?
Much more likely is, as you state, when the government wants something, they are going to come along and demand it. And if you want to keep doing business in China, you will have to provide that data.
This, while still a worrying state of affairs, is a far different scenario from 'all crypto is banned!' espoused by the writer.
Given that it is a fundamental theme of the original article (encryption effectively banned), why doesn't the author provide this information in the very same article?