I'd like to add my $.02 if I may. This only my experience, but it is nearly 3 decades of it. I use RK chains as a matter of choice and have for all of those years. I've never encountered a counterfeit one.
It doesn't matter which RK I've used. 530, 525 or 520. O-ring, X-ring, XW-ring or non-oring they all conform to a very high quality standard. Metallurgy or precision fit, it just didn't matter. I've had nitrided (gold chain) chains look like new after 6 or 7 years of use.
All that said, I went to Singapore back in 2005. We wound up stranded there for a week due to weather (typhoon) and couldn't take off. While there, we (all the motorcyclists from the deployment) went to a district in Singapore where all the motorcycle shops are. Not all were open but the few that were, found us entertaining.
As such, they told us about some the stuff they had, stuff we didn't get in the US. That's primarily what started conversations, us talking about gear they had that we didn't get. One shop, they were really up front and honest about it. They told us, alot of stuff was counterfeit. Brought over from Hong Kong. They told us to watch out for prices that seemed way too low.
Prices for real, brand name gear was just as expensive there, as here. So, it made sense that if something was cheap, it was likely counterfeit. They even showed us a couple of helmets. Same name brand...Suomy I think.....one was being sold for slightly less than what we'd pay here (not DOT though) and one was about 1/3rd the price. Same name brand. Same model of helmet. Slightly different graphics.
As we pondered the helmet thing, the guy helping us told us that wasn't all that was coming out of Hong Kong. Counterfeit everything he said. Hardware, wheels, shocks..all manner of stuff.
Most were obviously fake, like Öhlins shocks that were too cheap to be real. You could tell he said. A real Öhlins went for real money. $800-$1000 in Singapore dollars at the time. Counterfeits were around $180 SD. That's only bit over $100 USD.
That story told, I'd not be surprised if RK were also being counterfeited. They're a well trusted name in business. RK Takasago also makes sprockets, Excel rims and hubs, and a number of other motorcycle industry brand name standards. They also make TCC (Takasago Chain Company) branded bicycle chains and have since the 1950s.
To put an even greater emphasis on RK products, their chains and sprockets have been used for years by HRC in Grand Prix and MotoGP road racing.
I would not find your hypothesis that there are counterfeit RK chains out there to be a conspiracy theory. The weight of evidence, even at an anecdotal level supports the possibility. I'd say, go ahead and get your ducks in a row and contact RK US and see what they have to say. .....sean