I'm not sure if I'm missing something here, but we do see the original Kunlun die on screen, and Ma Gui and Fu You explicitly ask Zhao Yunlan to take his place. Shen Wei later mentions he knows his reputation, too.

But this guy definitely wasn't involved with Ma Gui when the Hallows were created, so he wouldn't be a source of wise Hallows-related quotes! Maybe the quotes are just later attributions, yeah.