Had this exact same experience, and you are the first person I know of that saw it as well. I distinctly remember (SPOILER) when they were on the roof, about to disable the device, going "I can't believe that Marvel allowed Lego to do this before their big movie blockbuster". For that matter, who was the marketing genius who thought that surmising the entire story arc would make for a good commercial at any time?
His name is Mads Nipper and I wrote to him and Jorgen Knudstorp (the CEO) over email the day after I saw the film. Sadly despite a day's research I couldn't find an email address for either of them that wouldn't bounce so I left it. I could have killed a tree, but in the end something came up and I moved on.
I just dug it out again. I was really angry. I'm almost glad it didn't get through. Here is a short excerpt:
What in Thor's name were you idiots thinking? Did you seriously believe that you'd engender goodwill in the audience by spoiling the film as it was starting? It's EXACTLY as if you'd shown an advert before a 1980 screening of The Empire Strikes Back featuring Yoda, a handless Luke and Han Solo in a block of carbonite.
For great shame, Jorgen. May your bare feet always find bricks.
My favorite kidsafe curse is from an old BBC radio show from the late 40's and early 50's, called The Goon Show. The main character would say "curses and naughty words". The BBC at that time was super-strict and you couldn't say curses and naughty words, so he would literally say it instead. Very funny.