I'm sure it's possible to guide them to originality. And, in fact, even Suno at this very early stage in its development is capable of creating original music, sometimes even by accident.
I had wanted to coax it to produce structured/"melodic" dark ambient music like this: https://youtu.be/2L-lA0xqzKo?si=SESlJhPjKvRyUeTm&t=614
What it came up with was not much like what I had intended. It appears to have interpreted "ambient" in the alternative way -- as in ambient café noises and background murmurs. What it produced was a conventional hazy ambient track with what seems, in a dreamlike way that's hard to grasp, like a conversation running in the background. Quite unusual! https://suno.com/song/45b23814-59e2-480e-9a2a-7c7a895b3957