I suppose you are right. I was taking AI to mean an engineered intelligence to be used in a machine, but just simply having it mean man-made, I guess AI is a term which summoned creatures could fall within. However, we don't really know a lot about how summoning in FFX actually works. We can see that fiends and aeons are made up of a myriad of pyreflies. Are humans also made up of multiple pyreflies, or do they all consist of one single pyrefly (aka soul?).

We also know that pyreflies lump together and create fiends, which seems to be a natural process in the world of spira. These fiends seem to have a form of intelligence, however simplistic it is compared to humans. Their intelligence would therefore not count as artificial. Likewise, summoners call forth aeons, which are essentially also just a bunch of pyreflies, like fiends, but arranged in a different structure, and with what seems like a higher level of intelligence. However, the summoner does not choose the form or intelligence of the aeons they summon. They seem to summon forth pre-defined sets of pyreflies, with a personality that is not possible for the summoner to alter. I don't know if we know how the intelligence of these summoned aeons come into being, so I'm not entirely sure if they are artificial or not.

People become fayth by their own choice, it seems. If their consciousness is transferred to the aeon exactly as they were as humans, isn't that a natural intelligence, rather than one that is artificially made?

Also this is an interesting intellectual exploration of how spira works!