Models don't have some self identity, beyond what is explicitly handed to them via a system prompt. There have been many, many cases of models identifying as different models by different makers as a basic identity hallucination. They train on enormous volumes of data including lots of people talking about certain makers and models (ChatGPT was actually a super common one given that it became the kleenex of the LLM world). Hence why vendors have to specifically tell it to override that, and if they don't you get lots of funny cases of identity confusion.

This isn't the big gotcha some people seem to think it is, and the whole news cycle about that was mostly by people who have no idea what they're talking about. It's actually a meaningless data point. But it's precisely the sorts of people who think that a few thousand free accounts surreptitiously snuck off with Fable.