The same could really be said about human teachers as well, though. An AI is frequently confidently wrong but so was my history teacher.

Don't get me wrong, I think this is a terrible idea. But we were already vulnerable to misinformation with classical schooling. To use your example, we WERE taught that Colombus discovered the Americas peacefully. It wasn't until I reached college that I learned the truth behind the discovery and colonization of the Americas, and I only even learned it then by doing my own history reading. Up until that point I had been taught that Thanksgiving was celebrated in memory of the happy-fun-get-along-times that were had between the settlers and the natives.

Kids are already taught ridiculous inaccuracies on purpose and while I hardly think an idea like this would improve that situation, I have to point out that at least accidental misinformation would be less objectively evil than what we already misinform kids about.