User blog comment:Miskos3/Fairy Tail Chapter 543: Hearts Connected/@comment-31694187-20170707191315/@comment-26099879-20170707220036

Which means the Demon Seed is no longer within Natsu's body. Plus as she rewrote it she clearly mentioned he is neither demon nor human in When the Flames Go Out.

But I think everyone wanted him to enter his Etherious form. :'(