It is not simple like that, anthropic claimed that they (Chinese labs) routed the api calls to Claude models to keep the illusion that Chinese models are also capable.

So it is not that the labs call the requests parallely and only return the internal version, but also serve those requests live so they can trick the users that the Chinese models are also great.

Which is very silly considering Chinese models are published to huggingface for everyone to test.

It is technically impossible, considering they need to serve them live and the token generation speed is a hard limitation. Just think about it, since us models hide their CoT, there will be dozens seconds delay before the first output token retuning to the user. And to predict the fake CoT correctly you need to at least read enough output tokens to make it believable. Then you have to hide their own model CoT to generate said synthetic CoT, which mean further delays. Adding up it will be at least 30s or 1m before you first seeing the thinking process.

I don't think nobody would notice such delays, because Chinese models do not need to hide the CoT like US models so usually they start emit text pretty soon