Naruto got Hagoromo's senjutsu.
It was never really stated that he got that from Hagoromo, for all we know that could have come with having ALL the biju in him, thus allowing him access to the Sage's Senjutsu. In fact, it would be highly implied that this new senjutsu came from having all the biju in him, because...
Naruto has those Truth-Seeking Balls around him, same as Obito and Madara.
Obito had Jyubi in him, thus having those Truth-Seeking Balls
Madara had the Jyubi in him, thus having the Truth-Seeking Balls
Naruto has all the biju in him, basically that is the equivalent of having the Jyubi in him, and he too has the Truth-Seeking Balls
Therefore, the Truth-Seeking Balls didnt have anything to do with Hagoromo's Powerup it was a powerup he began to get from the moment he got the 2-7 beast's chakra. Then the deal was sealed when Obito gave him Ichibi and Hachibi's chakra.