^ Yup, no doubt, they are edited out of continuity.
If anything, this is actually being done to (poorly) to show that Gwen will be saved.
Look, I too am a bit disappointed they made it so easy to figure out. I mean, to me, the story demanded that she die at the end of TASM2, which is what I've been arguing for the past year, but as more and more evidence has come in it has become almost blatant.
I don't think this is Webb. I'm sure he would have rathered the fanboys and all not see it coming, but as we've seen with other movies, the Marketing people can't be controlled. They just take the footage and put cool trailers together. And the trailers have been really good, but has just given so much away. Effectively, the Marketing people are idiots, as far as hiding things, but genius as far as getting the GA to want to go see this movie!
The point though is that this is not Webb telling the Marketing people to show us all of this so that he can play a little joke on us fanboys, by not having Gwen die in TASM2, but then to go ahead and kill her in TASM3. That would be beyond stupid. Look, Gwen's going to die. That's what she does. That's her purpose. So, as others have said, if it didn't happen in TASM2, then it would happen in TASM3. But remember, this series was originally planned as a 3 movie story. So they needed to tell the tale of Gwen in 3 movies. That means she would need to die at the climax, which is usually somewhere in the middle. This is why I've been arguing that she has to die at the end of TASM2, and I think I've convinced some along the way. And at this point, with what they've shown us, most others have jumped on board as well.
So strap in and prepare to see a sobbing audience, because this one is going to hurt!