1) Who created the systems that generated the "synthetic" data? It didn't materialize out of the ether like magic... By definition, all data that exists in our information systems is human-generated, whether it be a description of a dog, a video of a dog, or audio of a dog, to physics/math, and everything in between.

2) Even if you concluded that this "synthetic" data were not derived by man, do you think it's possible to drown out and override all human-related correlations (mimicry) without training on many orders of magnitude more "synthetic" data?