I was puzzled a bit, then realized they only handle schematics. Saying "PCB schematics" is weird.

A schematic is just a representation of a netlist, something where text is more than fine since the graphical form is only for human consumption. An LLM is actually a pretty good fit to cross-reference datasheets and netlists.

Would it be actual PCB layout I would be skeptical as LLMs are quite poor at anything spatial. For schematics however, it could work quite well as a double check.