thoughts
Someone had an interesting explanation to this chapter and what I think makes the most sense. Natsu declaring and firmly believing his identity as a human, not a dragon nor demon may be exactly what he needs to harness both powers. I don't think both powers are necessarily gone, just dormant and waiting to be accessed freely by Natsu.
It was implied that many of the dragonification cases happened due to DS losing their sanity. The reason this happened is because they lost all sense of their identity. But by affirming his identity with zero hesitation, Natsu is now perhaps closer to Acnologia who can freely switch forms. It probably took Acnologia centuries to figure this out.
Next chapter might have August, and we may see August noticing Natsu's change and might explain this whole thing. I don't think it was a bad chapter, really. If anything, I'm quite curious to see what will happen from here on.