Well isn't the context of how it all happened more important though? They didn't spoil how Aqua got corrupted, Ventus waking up, Kairi's death, the Lich, the Guardian housing Terra's heart, the scene with Xemnas and members 9-12, and other big reveals that happened in the game.
Sort of? The problem came from the fact that we were shown more of the game than we expected. There really weren't many important reveals
left to experience by comparison. It also wasn't hard to connect the dots for certain things like the Anti-Aqua plot, given that we were pretty much shown every stage of that story.
How Aqua got corrupted didn't even matter in the end, since it held no bearing on anything else in that plot (or any part of the game really), and never actually gets referenced or addressed again. That said, we actually
do see her fighting SoD in the trailers without her Keyblade, as well as her physical transformation as she's sinking into the abyss.
We technically did see Ventus up and awake in at least two trailers.
The scene with Xemnas, Larxene, Marluxia, Demyx, and Luxord, again, held no bearing on the plot, doesn't lead to anything or have any connecting scenes, and is pretty much self contained. In that sense, can we even call it a true story beat, or just fluff? Still, it's something I suppose.
We see Xion and Roxas brought back (what facilitated their returns was in the background, and wasn't an actual reveal in and of itself). We see Lingering Will and Terranort. We see Vexen, and even got implications that he might be a spy of sorts in the trailers (based on the diologue). We see Demyx is back, and norted as well. We see Ansem The Wise and SoD discuss Subject X (though we didn't have the context for that). We also see Ansem the Wise talk with Ienzo. We see Repliku, as well as the moment Riku left his broken Way to Dawn (which was also spoiled) behind for him. We see Chirithy and The Final World, as well as the semi transparent Sora running through clones of himself. We see Young Xehanort state his reasons for being in the Toy Story world, and foreshadowing their "missing darkness". We see Vanitas attempt to extract Ventus from Sora, as well as what he and the Unversed (who have also returned) were doing in Monstropolis. We see Dark Riku. We see Larxene talk about the New Seven Hearts. We see Luxord talk about the Black Box. We see Vanitas in the restored Land of Departure. We see everyone die, and Sora's subsequent breakdown (as well the
only diologue from both him and Riku that followed that). We see Riku protecting Sora. We see every boss for every Disney world. We see every summon/link in the game. We see every minigame, except for maybe the one in Corona. We see playable Riku. We see every form, and nearly every transformation. We see the Xehanort Replicas, hear that he intends to join with them, and see the arena for the final fight (so pretty much everything leading up to the final battle). We see Let it Go. We see Siax meet with Lea. We see Anti-Aqua of course, as well as her attacking Riku. We see Mickey's new Keyblade then as well. We see Sora find Master's Defender. We see Sora rescue Aqua. There was a point where they officially released 10-15 seconds of Sora fighting Aqua, spoiling that he does, in fact, fight her too. Aw, and we see every single member of the Seekers of Darkness. Also, Young Xehanort and Young Eraqus, as well as Scala Ad Caelum.
There's probably more I'm forgetting, but I distinctly remember seeing all of this stuff in the official promotional material for the game. It may not be absolutely everything there is to spoil, but it's more than a good 80% of the game's actual content. And that's definitely enough to sour the experience for many players.
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Anywho, onto the topic. I'm honestly not sure what to even expect at this point. Like, I'm not the least bit excited for it if the base game and that last trailer were anything to go by, but I'm curious about what they decided to include in the end. If I had to guess one thing though, it'll probably be composed mostly of more reused assets.
