Oda was hesitant to reveal too much in Wano, because he didn't want to reveal that Wano is the Ancient Kingdom, yet. There's still a lot to do in Wano: Onigashima's backstory, King's backstory, Zoro's backstory, Pluton, Oden's dream of opening the borders, Toki's Fruit.
Not to mention, this:
Oda was foreshadowing the Revolutionaries going to Wano AGES ago in Dressrosa.
Now that Kaido's gone, those weapon factories are pretty defenseless. I think the Revolutionary Army will make good use of all of the weapons Wano produced under Kaido's rule: the tyrants arms will be used to create revolution. I like it.