I think we may have put too much stock into our act prediction stuff.
Let's face it, none us are actually Kabuki experts. It's all based on Wikipedia and this page
https://globalshakespeares.mit.edu/glossary/kabuki/
I really see this as the start of the end for the Wano arc. That's generally speaking how Oda does things. We've had the big flashback, time for the fights and conclusion. There'll be a few twists and turns left, but the alliance certainly isn't facing a crushing defeat and then the fights starting again. If there is to be five acts I reckon this act is finishing pretty quickly, maybe with the alliance arriving on Onigashima and act four will be the war itself.
I'm also not sure if Oda is going to want to cut back to the rest of the world again until the end of the arc.