I think that's because in the first case, the amp modeller is only replacing a piece of hardware or software they already have. It doesn't do anything particularly "intelligent" from the perspective of the user, so I don't think using "AI" in the marketing campaign would be very effective. LLMs and photo generators have made such a big splash in the popular consciousness that people associate AI with generative processes, and other applications leave them asking, "where's the intelligent part?"

In the second case, it's replacing the human. The generative behaviors match people's expectations while record label and streaming company MBAs cream their pants at the thought of being able to pay artists even less.