On top of that there's plenty of foreign reporters there, and plenty of foreign diplomats who would also notice.
Those policies sound even more strict than what we've been doing in Australia, and we had 2 weeks with 0 locally transmitted cases. With procedures like that it makes sense they have covid under control.
(The times when news got out.)
The ability of Chinese authorities to suppress the information domestically (again, recent crackdowns on using social media for self-journalism), as well as to influence Western sources, shouldn’t be underestimated. I wouldn’t mind listening to that podcast though.
I know about COVID test results required for travel, but I don’t take it as much of an indicator if you consider people outside major cities who do not travel much (especially now that there’s an extra barrier to it) and may just suffer from virus outbreaks in localized clusters where they live.
Either way, what we don’t have is reliable numbers of how many people were tested, and how many of them were positive, across China.