> From a ML-perspective adding any unrelated country name shouldn’t matter at all.

It matters to humans, and they've written about it extensively over the years — that has almost certainly been included in the training sets used by these large language models. It should matter from a straight training perspective.

> but that should be easily verified if you try this same exact experiment on other models.

Of course, in the real world, it's not just a straight training process. LLM producers put in a lot of effort to try and remove biases. Even DeepSeek claims to, but it's known for operating on a comparatively tight budget. Even if we assume everything is done in good faith, what are the chances it is putting in the same kind of effort as the well-funded American models on this front?