More like Horakhty created the manga verse where Yugi, Kaiba and the duelists reside in.
There are more to Yugioh than just the anime verse. The OCG lore verse for example, were not made by Kazuki Takahashi, they are distinct franchise with their own stories, authorized by other Konami employees.
And let not forget, Yugioh as a whole is not just a product of Takahashi-sensei, it's also product of Konami as well. This is especially true in this case. DSOD was canonical to the
original manga made by Takahashi-sensei, while the anime deviated from it and gotten written by other authors like Shin Yoshida.
What I want to say is: Takahashi-sensei's word is not final, especially in a franchise like Yugioh that have shitloads of Creator Gods that created their own setting:
+Numeron Dragon created his own small multiverse
+Metaphys Executor is a walking talking multiverse
+Ogdoadic Gods created their own universe in their own cosmology
+Ryu Ge Mistva (Although I just checked again, so far the lore only said he created the "world" which seem to be the planet)
+Regenesis Lord created his own "world" (also need more lore to regard this "world" to be universe)