In no way was Enma storing Oden's haki confirmed in this chapter. In fact, I'd say the chapter provided evidence
against Enma storing Oden's haki. Oden's haki should be intimately familiar to Kaido. Had Zoro been releasing Oden's haki through Enma, Kaido wouldn't have called it "strange".
We could have seen phrases like:
- "That haki seems oddly familiar"
- "That haki... Oden!!!"
- "Why is Oden's haki flowing from his katana?"
Oden gave Kaido his lone grievous scar and left a deep emotional trauma on him. There is no way that Kaido just doesn't recognise Oden's haki.