Konan said that who was told by Nagato who in turn was told by Obito and Obito was told by Madara. Madara simply made the observation based on his own pure Rinnegan powers. That does not confirm Sasuke has all the six paths. Sasuke's Rinngan is a dumbed down version requiring recharge times, that too when he has both Hashi and Rikudou chakra lol. And Manga never confirmed Sasuke has all the six path I don't know why even though there were so many occassions Sasuke could've used it post time skip. Read the thread I posted earlier...

If he ever uses them then I'll believe it. For now he doesn't have them in my book.
So who taught Obito? Madara
Then who taught Madara? Madara (or BZ).
If BZ can teach Madara by just seeing Hago's powers lets assume, then there is no way Naruto can't teach Sasuke having fought and seen all six paths of Pein...

And even after 12 years still we see Sasuke doesn't have all of them.