Yes, many people assumed this. Here's the first example I found (scroll through ...

forrestbrazeal on April 18, 2023 | parent | context | favorite | on: AI song featuring fake Drake and Weeknd vocals pul...

Yes, many people assumed this. Here's the first example I found (scroll through the thread for many more): https://twitter.com/Russ_Wilcox/status/1647602468623114240 (Note that this guy was smart enough to ask the question - imagine how many people saw "AI-generated song" and just uncritically assumed a computer spat out the whole thing, chatGPT-style)