Isn't that always the case though? To achieve something we know is already going happen lol. It's not like we don't know if Sanji is going to beat Queen or not, we know it's going to happen. The difference is, how well can you do it? How much will you show?
Giving villains/protagonists more opportunities to show off new attacks/impressive art that can be immortalized in the manga is a good thing. It's not like we are dealing with bleach where every fight is 5-6 chapters long, including the lowest end captains and villains. In one piece, getting 1 or 2 of those personal chapters is an accomplishment since it's a rarity for Oda. And don't get me wrong, I love bleach.
Anyway, you and plenty others might be right. It could just be over and Oda showed it all. Maybe Jinbe, Franky, Brook, Usopp, and Chopper or any combination of them tag Jack instead and get even more to do. Maybe Nami helps Raizo defeat Fukurokuju. Maybe Chopper fights Numbers or helps Neko against Perospero.
So many possibilities, we are just here at a moment where we don't actually know what comes next.