This doesn't really spoil the plot. This trailer didn't tell us anything more than a synopsis/summary on a theater website wouldn't. The teaser trailers these days are what trailers themselves should be, too many of them spoil shit so I don't watch them, but this teaser does a pretty good job of showing you enough to give you an understanding of what it's about without actually spoiling the story.
well now i know that mjollnir is gonna get destroyed and thos is gonna get defeated and captured.
i already know loki is in the movie (and most likely one way or another will help thor and betray him)
i already know he will face off with hulk (as one of the main events possibly?)
not to mention the "ruined joke" which would have been hilarious in the theater but now everyone is aware and waiting for this moment....
imo trailers shouldnt show this much of a movie. take batman vs superman. they already showed batman and his reasoning to fight superman. they already showed doomsday and them teaming up against him and they already showed wonder woman, who according to the movie should have come as some kind of suprise/ mystery....
a trailer should just make you hot for the movie. it should get your interest and show just very few non spoilerish pics.
i just cant stand spoilers and ****ing hate trailers. definitly never gonna watch one again