alt Hacker NewsThis isn't true at all in general online discourse. Maybe on X, in which case I'd recommend getting off of X.
It's overwhelmingly brought up when talking about Japan (and sometimes Korea) in comparison to the US (or EU). With Japan (or Korea) being the high-trust culture in that comparison, and the US/EU being the low-trust one.
I guarantee you can do a search across mentions of high/low-trust culture across online platforms in the last 12 months and the large majority will be these contexts, i.e. Western countries described low-trust, not high-trust.
I've definitely seen it used both ways, comparing Japan to other countries as well as India/Africa.
I wouldn't necessarily call it a "racist dog whistle" myself, though - there is a very real pattern that's being pointed out but the reason I made the GP comment is that from my experience I would assume that Chinese culture is about as trustworthy as the West.