That's fair and you're right that they do spoil things a certain amount in live letters and keynotes. They spoil it enough to make you excited, but without revealing everything. It does reduce the surprise and excitement of the story itself though, sadly.
For example, the Shadowbringers keynotes told us "you will be told the story of the Warrior of Darkness" and you will "go from area to area, restoring darkness to each area". Simply doing 2+2 made you realize this would be via fighting dungeon/trial bosses, because that's how the game works. And then the launch trailer spoiled who certain primals were.
The Endwalker material spoiled that it was the end of the arc with a poster of you-know-who and it was obvious who we'd be fighting in the trials. It was heavily hinted we'd be going to a place involving the ancients due to some concept art, although I did not know it would be "going back in time". It was heavily hinted we'd be going beyond the moon when they dropped the 1.0 trailer right before release and made me fairly confident we'd be going to the Dragon Star, which technically we sorta did.
So I get what you mean here.
(I do want to say, that in all cases, they did not really spoil Hades or Meteion, they tend to keep who the last trial boss is sort of unclear, it could have been Vauthry and Zenos/Fandaniel/Hydaelyn/Zodiark/etc.
The story is also very nuanced, so you can have the key elements spoiled but still enjoy learning the nuances. It's like how when you go to watch a Superman movie, you know the main character is Clark Kent/Superman and Lois Lane, you know they will win, but you don't know how and what exact hurdles they'll go through, and that's ultimately what you're going there to find out.)
They should have put it on the lodestone earlier. I did do a scroll back to see if they did and also used archive.org and they didn't have them up earlier. The keynotes were also not transcribed and put in the live letter forum like live letters are, so you couldn't actually read an official summary like with live letters. The specs also aren't actually shown in the trailers.Probably should have just lodestoned everything abou5t specs regardless so people who don't interact in the social media/youtube side of this game could be on the same page as those who want to watch and know everything. I feel that at least would warrant getting the word out on the official platforms for.