I actually had these thoughts when reading the bitcoin whitepaper. It seemed to me that the author had surely written other research whitepapers, and thus there should be definitive artifacts and writing styles that can be used to attribute authorship [1].

I don't see why this has to be limited to the capabilities of an intelligence agency. Perhaps they have the motive, but I'm sure private citizens could perform the same data mining queries (without mass surveillance).

Either way, this post presents zero information and just unsubstantiated speculation.

[1] https://en.wikipedia.org/wiki/Stylometry