It seems like there is some kind of grand secret about the gum-gum fruit that Luffy eat. Perhaps this is set up for Luffy for when he engages Kaido for a 3rd time. We may see Luffy's awakening! Its been a long time coming. The time feels about right too.
Also Zoro's current predicament is hilarious. I can't wait to see what else he does in this arc.