And no, LLMs are not perfect. They're non-deterministic.
And no, even if they were perfect my statement was that it is irresponsible to teach a child to trust an LLM. Even if it was perfect on these topics, as they move forward in education that trust would later fail them.
That is a problem both ideologically and pragmatically. You have to think long-term.
On a side note: ask an LLM to write a story at a 4-9 year old level. Work with it for awhile doing iterations and it will hallucinate a previous detail or change a character name as context rots. Lots of other examples of "basic" topics that still produce hallucinations.