I see it more like a natural phenomenon close to the reality of some conditions than some surprising phenomenon. There are a few reasons and what we're experiencing are related. One of them is automating reasoning which enables at scale work (reasoning) across domains, regardless. The other is that domains are actually much more interconnected than it would seem looking from outside. While this has been the subject of surprising discoveries for decades (at least) I also don't see how it can't be otherwise. Nature doesn't have different laws based on how we chose to artificially split it in "domains".
> There's no particular reason to believe that solving math theorems generalizes to engineering or robotics without a whole lot of additional work
that "whole lot" is only a lot in human time (the typical "man-month") which is what is being sped up here.