Huge fan of the Kingdom Hearts series, and I create (Lore Explained) posts to help people better understand the story! Feel free to DM if u have lore questions!
All we know is that the Ursula in DDD is a phantom version of herself; that is really all we are told. She is either a fake summoned by Ansem to interfere with their exam, or it is her KH2 self who time-traveled after her defeat.
Yeah, because they are both godlike beings and one of them is the ruler of their own world, it makes sense that they would have some knowledge about the Keyblade, especially since Genie has been around for many years.
