Personally I think the approach of combining deep learning with MCTS to beat Go was obvious to anyone sort of familiar with each thing, and with a good funded team could be done in a year or less, but a lot of 'experts' were ignorant of one or more of the areas. The uncertainty should have revolved around when some group would get around to writing the software and scaling up with powerful hardware. Implementation details, the theory work was already known.
My own lesson from this is that if all that is needed is tough engineering work (but not really new theory) that work could literally arrive in a week instead of the x+delay time it might take from scratch, because some group could already have been in the process for about x time that isn't public knowledge. AlphaGo kind of came out of nowhere; there were early signs with papers on using deep learning techniques, but I don't remember any public commitments to much. That just indicates companies are still quite capable of doing secret projects. If they had a secret new theory, too, it could be even more amazing. I know of one startup in particular that's been securely at the top of its niche because internally they have secret CS research unknown to academia.
The OpenAI initiative may be useful from the perspective that if they've shared what probably shouldn't be shared, at least we can suspect something is imminent and try to plan a last minute stand of getting it right first, vs someone like Google doing all the research in secret and then bam, unleashing UFAI.