The Straw Hat flag makes sense: they probably moved it to the front of the country, so it can be seen by people approaching Wano (they want to open the country, remember).
No Big Mom, Kaido, Pluton, barely any Beast Pirates, no Big Mom Pirates, no one entering the country
We didn't even see Zunesha/the Minks.
But overall, wow, we could have explored so much in Wano, and... oi...
Teach is the only Yonkou that can save Wano from itself