If that’s true, yes it absolutely caused the fights to lose focus. Probably also why the Arc in general has felt very strange pacing wise. With how everything has gone I honestly feel like Act 3’s big dramatic moment of tragedy was supposed to br Oden’s flashback - even though it was played heroic and not tragic - because nothing else comes close and it was moved to the start of Act 3 rather than the end just so Act 3 could be the entire Raid and Act 4 could tie up because Oda did not have enough time. Something has felt off this entire Arc. Oda rushing to meet expected milestones would be it.
Should be noted that, while Oda was pressured into doing something for chapter 1000 by his editors for a promotional campaign, he only started feeling that pressure around chapter 980. So he was well past Oden’s flashbacks by the time he started to shuffle things around. Which makes sense, a lot of the events of the raid only have narrative resonance because of the context those flashbacks provide.
Looking back, it feels like the things that ended up on the back—burner during this reshuffle were some of the smaller fights like Kiku vs Kanjuro and Yamato’s introduction.
Chapter 1000 did not feel very special to me honestly entirely because it felt rushed. Heck, there seemed to be setup where a straw hat would be left behind on each level as the rest rush to the roof allowing for one on one personal fights, and the levels went nowhere. You don’t introduce as many floors as you have main cast for any other reason than to leave one behind every floor to show the gauntlet that the overall fight is. And yet they just skip floors. Like what?
Re-reading Act 3 again, I think Onigashima is intended to be less of a tower crawl and more like a multi-layered theater stage. Kabuki stages traditionally have a main front stage being flanked by two additional stages to the left and right, the audience sitting in the center (and frequently interacting with the actors throughout the play), occasionally an additional stage that cuts through the audience to bridge the right and left stages, and then additional audience members sitting outside the stage area. And looking at the skull dome from above, the layout is similar,
So you got the samurai and beast pirates - representing those who are being effected directly by the outcome - serving as the audience on the performance floor, figures like CP0 and the Marys as the outermost spectators representing the outside world observing these events, all the events that effect the overarching plot (Wano, Orochi, the Yonko fights, etc.) are in Kaido’s castle and the roof (the center stage), many the supporting fights and more character-driven fights end up in the left and right towers (the side stages), and developments that have an immediate effect on the raid‘s chances (the Oni Ice virus, Tama’s dango powers taking effect, Kaido demanding Momo’s surrender, etc.) all bleed into the pseudo-audience on the performance floor. If I recall correctly, the raid even officially begins with the 9 Scabbards emerging behind a curtain from the rear end of Kaido’s castle and stabbing him, subsequently taking the fight onto the performance floor.
Oda is definitely committed to the theatrical elements of this arc.