So what you're saying is that we lack a reproduction study?

Great; let's design and fund a study of the development of artificial intelligence that's as causally divorced from the ~extropian days as possible and see what they come up with. Barring that:

Basically that is what we have up until the early development of transformers; I don't think the authors of early deep learning or transformers papers were part of the rationalist sphere. The rationalists famously didn't believe neural networks or deep learning could achieve anything close to AGI.

So there are several diverse traces of intellectual development leading to modern estimates of AI risk and they vary from low to high without a lot of correlation back to the school of thought they trace back to. This leads me to believe that overall we have fairly good coverage of cultural ways of thinking about AI and AI risk, and aside from a minority of holdouts (LeCun) they have high enough x-risk or catastrophe estimates to take it seriously (e.g. >1% over the next few decades).