There are many definitions of AI (eg. there is some mathematical model used), but machine learning (which is used in the large language models) is considered a part of the scientific field called AI. If someone says that something is AI, it usually means that some technique from the field AI has been applied there. Even though the term AI doesn’t have much to do with the term intelligence as most of the people perceive it, I think the usage here is correct. (And yes, the whole scientific field should have been called differently.)