After a very long time in movie history, the marketing campaign is done how it should always be done for every single high stakes movie. I've been saying that for over a decade at least. It's been a lot of disappointment over the years, that's why I'm very happy and excited for Endgame.
Trailers for movies like this shouldn't show anything regarding the plot. Even more so when you know a movie has unexpected twists and turns in it. One of the reasons why I say most people these days are shallow, have ridiculously mindless logic about movies and in all honesty don't deserve movies of this magnitude is this - they want to see a lot of footage, especially juicy parts, but at the same time they don't want to know anything ''big'' about the movie. And then they're mad when the trailer shows too much, but they don't realize they ask for too much to begin with. That's just not how it works.
The main problem with trailers is exactly that - showing juicy stuff. How it works for me for example is, I see a trailer, I watch it a few times and I remember it completely whether I want to or not. And then, when I go see the movie, I just keep ''deleting'' trailer scenes from my mind as they show them in the movie. I know exactly which scenes have been shown and which haven't when I'm watching the movie. And that is a huge problem because it takes away the surprises the movie has completely whether they want to or not simply because of the tiny, juicy trailer footage.
For example, that was a huge disappointment for me in Fast and Furious 8 (The Fate of the Furious). I'm a huge Fast and Furious fan too and those who follow it will know what I'm talking about. There was a scene in the trailer for that movie showing Jason Statham's character taking off his helmet inside of a plane, that's it regarding that scene. I remembered it, of course. And then, when I watched the movie, there was a scene in the middle of the movie where Jason Statham's character gets shot and presumably killed. Even a few scenes later, one other character SAYS he's dead (to throw off the other characters).
It should've been ''wow, he's dead, he can't be dead, please no blah blah blah'', right? That's what the writer and the director were going for. But, because they showed the footage of Jason's character in the back of the plane in the trailer, I was aware that the scene from the plane didn't happen in the movie yet and that's why I knew he wasn't dead. A huge twist gone down the drain just like that, ruined. Just because they wanted to show something ''juicy'' or ''cool'' in the trailer.
With Endgame, it's almost perfect. They have fake scenes, digitally removed content from the real footage and trailers that don't show anything other than transitional scenes or minor scenes that don't reveal the plot itself. Unfortunately, almost perfect. For example, they made the first trailer perfect, but they screwed it up with the second one regarding Tony Stark. They showed him and Nebula in the Avengers HQ, thus spoiling that he was gonna return back to Earth. They showed Ant-Man out of the Quantum Realm, that's another screw up too, but other than that, it's perfect.
They have to be careful what they show. Almost none are unfortunately.