I think the simplest answer is probably the real answer here. An article had inaccurate information, and all involved parties responded with the same story because they were all responding with the truth.

The alternative is the Chinese government inserted a chip onto boards. Which would have required a modification to the board as well as bypassing all of Apple's own hardware security measures. This sounds like an interesting story, but seems a lot less likely. Would the people planting an additional component not expect a company to inspect their own boards when doing normal checks?