A few years ago i ( and i'm sure many others independently
) had the idea that it would be cool if the manga went into the direction where it is revealed that casting jutsu is a universal ability that does not have to depend specifically on one bloodline or genetic trait such as having a special eye. That would mean that Naruto could be able to use any jutsu ever seen in the manga given that he unlocks the ability. Some things pointed to this direction: everyone has one elemental affinity, however jounins can master 2 elements and geniuses like Kakashi even 3-4. Then there was the Sage who mastered all. Later in the story it was revealed that the Sage created the ninja world, and that in this creation the god tree's chakra was given to humans. So we have the universal thing that is ultimately the source of all known jutsu, that is the chakra of the god tree that the Sage had in himself. And my guess is Madara mixing his own and Hashirama's chakra created the kind of chakra that is the nearest thing to the original god tree chakra. That is why he is able to use jutsu that were supposed to be usable only with the proper eyes. By this logic eyes are just tools to focus the power of creation (creation of elements, illusions, movement, etc.) in a specific way, so the eye is just an amplifier. Which means that if Madara can do a small Susano that we saw in this chapter without his eyes then his eyes can amplify the power of this Susano to be 1000 times more powerful. And of course this also means he will be able to use jutsu which he would barely be able to do otherwise, so he didn't even bother doing those until he doesn't have the eye. But on the other hand this also means that if Naruto has huge chakra he may be able to use a jutsu without this amplification that the eye gives. And if anything can be done with the "god tree" chakra, then one could even temporarily change his eyes and body into whatever bloodline's body/eye he wants, Naruto would be able to temporarily change his eyes into sharingans or rinnegans even
And we know that all 9 tailed beast gave their chakra to Naruto, the sum of all 9 types of their chakra should be the "god tree" chakra. But i guess this should happen only in the very end of the manga, right now it's much more probable that Naruto's chakra can be used as the fuel for Sasuke's eyes to transform into the rinnegan. There were already hints for this, but now we have one more: Madara mentions that either one person has both powers or the 2 sides collaborate, here the 2 sides are obviously Naruto and Sasuke. And what a coincidence: for Naruto to really have all chakra types of the 9 tailed beasts he needs the Yang (or was it Yin?) part of the kyuubi's chakra. If his father gives him this gift then Naruto should be able to put together (for a limited time) the god tree chakra. And then we finally have the big final boss fight of Madara vs Naruto+Sasuke that we expected long ago