I think this could be seen as a proxy for evidence that there's some degree of reasoning, if we think we can identify specialized features that always become involved in some kinds of outputs. It's not proof, but it's not nothing either. It has some parallels about research on human brains are conducted, right?
It does have parallels to the human brain, absolutely. We've been studying the human brain in similar ways for much longer though and we still don't know much about it.
We do know what areas of a human brain often light up in response to various conditions. We don't know why that is though, or how it actually works. Maybe more importantly for LLMs, we don't know how human memory works, where it is stored, how to recognize or even define consciousness, etc.
Seeing what areas of a brain or an LLM light up can be interesting, but I'd be very cautious trying to read much into it.