point is everyone scrapes data from the internet. Do you think there is at least one page on the internet that mentions Claude as an AI? Well, then it's part of the training material.
Yes, that's why Claude might think it's ChatGPT from time to time, because it scraped a url that contained chatgpt conversations.
But the reason why Kimi thinks it is Claude is different, it's because chinese companies make thousands of fake accounts, fire prompts at Claude and train their models to imitate Claude.