of course it wouldn't be unnatural for HSDS people to mention the guo couple...
...since the only people to mention them were in the beginning of the book, like GX, Z3F, and the monk WuSe. in the world of HSDS that ZWJ lives in, the only person that would have known them personally would be Z3F...and the only reason they are mentioned is because of the heavenly sword and dragon sabre.