It's hard to give an exact answer to ur question because we don't know exactly what's happening.. the only thing clear is Naruto using Kyuubi's chakra and gaining some new powers.
It's not just the body flicker tech but a new sealing technique similar to So6p's plus sensor abilities and probably more powers we haven't seen yet... So he is doing all these new techs without any prior knowledge of it. We can all speculate as to why it is happening and give our own opinions// I created a thread a while back see if you like the reasoning.
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