Nobody ever hypothesized it before it happened? Hard to believe.
It is somewhat parallel to the story of Columbus looking for India but ending up in America.
But I'd go further: even abilities that do appear "emergent" often aren't that mysterious when you consider the training data. Take instruction following - it seems magical that models can suddenly follow instructions they weren't explicitly trained for, but modern LLMs are trained on massive instruction-following datasets (RLHF, constitutional AI, etc.). The model is literally predicting what it was trained on. Same with chain-of-thought reasoning - these models have seen millions of examples of step-by-step reasoning in their training data.
The real question isn't whether these abilities are "emergent" but whether we're measuring the right things and being honest about what our training data contains. A lot of seemingly surprising capabilities become much less surprising when you audit what was actually in the training corpus.
Some would say it still hasn't (to an agreeable level).