The big spoiler in the Heavensward opening/trailer was a huge mistake. (spoilers obv)

[Aeyis]

I am not off the mark though, I am 100% correct in that putting spoilers in a trailer is a terrible move from a business standpoint, and the spoiler warning only makes it worse in that regard because it will turn away a good chunk of potential buyers.

You are all just looking at this from the player's perspective, repeating over and over that oh, there's a spoiler warning so it's okay! That's called missing the point. But it's okay, my message clearly wasn't for your ears anyway.

Have you ever seen any opening for any japanese game, like ever? They always contain tons of spoilers.
They are typically also quite meaningless for new players since they dont know the characters, or how to interpret whats being shown.