"Original Content".
Is it content? Yes.
Is it original? That depends on the context. What do you ask about, in what context? Where is it placed? Which AI? How was it trained? How does it replicate?
If someone generates an image, it is original in that narrow context - between them and the AI.
Is the AI producing originals, original interpretations, original replications, or only transforming other content? I don't think you can make a general statement on that. It's too broad, unspecific of a question.