A perception that many movie trailers give away way to much, effectively the entire movie, is a common thing for internet complainers to complain about. I think it's a complaint that's not as accurate as they make it seem.
I find it amusing how certain people often are that a trailer revealed everything when they still haven't seen the movie. Remember, no matter how much you may think a trailer has revealed all it's cards to you, it's still only 2 minutes of a two hour movie. I know of a few movies I could make a trailer for that seemingly reveals an entire beginning, middle and end while still not showing the actual final act at all.
It's likely they grossly under estimate how much a movie can do. The way I see it, if it was even hypothetically possible for a 2 minute trailer to truly give away everything about a 2 hour movie, it wouldn't have been a very compelling and worthwhile 2 hours anyway.
I find it especially annoying when they act like it's a modern problem, that the tendency to give away too much has increased since like 2000 or something. Have they seen any classic movie trailers? They were often quite literally a narrated summery of the film, in chronological order, like Richard Burton's Alexander The Great. And with Star Wars, the pre 2000 Episode I trailers gave away far more then any SW trailers since.
With modern trailers, no matter how much they show, that the scenes are in a mostly random order highly skews one's ability to actually guess how the movie will play out. For some reason the trailers for The Dark Knight had me certain that the confrontation between Batman and The Joker that happens in the Street (where the semi truck gets flipped over) was the final confrontation. Not sure why but it did.
What prompted me to do this was partly this article about the Terminator Genysis trailers. Now I don't give a crap about that movie, but he talks also about Terminator Salvation which I enjoyed, it's the only Terminator sequel I really like, but still flawed thanks to still being bound by the mutilated canon of T2 and T3.
He says that the reveal of Sam Worthington's character being a Machine was an important dramatic moment in the movie, therefore it was stupid of the trailers to give that away.
No matter what the trailers had revealed, you'd have to be a brain-dead idiot to not know he was a Machine right from the start. It begins with him about to be executed donating his body to science and thus signing it over to Cynbernyme. Then he wakes up all Rip Wan Winkle like in the future having not aged at all.
See I've talked before about why I feel the value of surprising the audience is frankly overrated. The reveal of his character being a machine is a source of drama for him and the characters around him, the notion that it's meaningless if the audience already knows is frankly a stupid simplistic way to look at it.
This reminds me of how people claim that it'd be sooooo horrible for any new Star Wars fans to watch the films in chronological order first because then the "I am your Father" scene looses it's impact. To me if you think that scene's impact and importance is dependent on the audience not knowing then you're the ones who don't appreciate the scene. The scene's importance in the story is that Luke learns he'd been lied to. And I think it's Mark Hamil's best acting in the trilogy.
Let's speculate while we're at it. If the Prequels weren't Prequels, if they'd been made first. Would trailers for ROTS had given away Anakins' fall to the Dark Side? Would it really be considered a twist without the future already being seen given all the foreshadowing in episodes 1 and 2?
I really don't mind knowing what is going to happen at all, because my mind is still curious about the details of how and why. Revealing that John Conner becomes a Machine in trailers for that stupid looking new Terminator movie makes the viewer wonder "How the Frak did that happen".
So no, a trailer giving away what seems like a "twist" does not equate to giving away the entire film.
Update: I have a new post that is sort of a follow up to this.