Yami Yami no Mi counter DF's abilities, nullifying them, when he makes contact. He demonstrates that by grabbing and hitting a Logia type, something that, so far, only happened with gimmicks or moments when the user was not expecting, like Dragon sneaking on Smoker, or Luffy rocketing himself into Smoker AND Ace.
At that point, the only thing to explicitly counter Logias. No gimmick like water making sand solid (which is funny, because Ice is fine, but wet sand not so much), or rubber countering eletric powers.
"I also never said Haki was planned just foreshadowed". That's a definition problem right there.
Foreshadowing is something that the author does on purpose. Intentionally dropping hints that will be later used on the story is foreshadowing. Going back and retconning stuff isn't foreshadowing, is just retcon. Which is not something that I said Oda definitely did.
I BELIEVE he did, but he really could have planned all these things all along.