Do NOT watch the MIB2 trailer on the Ali DVD!

I hadn't seen the trailer in theaters so I made the mistake of watching the trailer on the Ali DVD. It has what I think is a MAJOR spoiler!
Don't worry, I won't reveal it here.
I didn't know how they were getting Tommy Lee Jones back after he had his memory erased in the first MIB, until I watched this trailer. It's no secret they are, but I purposely avoided finding out the method and how it plays. This stupid trailer reveals everything about it, and gives away some great jokes too. It explains way too much! Now I know how they get K back and why! ARRGHH!!!
Why do the studios do things like this?!

It just ruined a major plot point in a movie I was looking forward to seeing. Now I don't know if I'll go, out of sheer principle!
You suck, Columbia/Tristar!!!
Blunt, yes, but I mean it!

 

What gets me about this trailer is not that K comes back (that's obvious), but how it was presented. It just gives too much away.
Now I know:
K is working in the post office where J finds him. He somehow convinces K to come with him to MIB headquarters. He has to get K back because K has something in his memory that will aid the MIB (quite possibly for the major conflict of the film). We see that K is now a fish out of water, arriving at this strange place (like J in the first MIB) and not truly believing any of it. He takes K to the deneuralizer where it can be assumed that K gets his memory back. I think it's hilarious that K is working in the post office, knowing the powerful position K was in before. The scenario of K not knowing what the heck's going on (while once being a big part of the MIB) already presents some good comedic situations in my mind.
My point is, did we really need to see all of this? I know K's coming back. Did I really need to see all of those details? Aren't the best trailers those that give you a taste of the film without giving too much detail away? This trailer presented in sequence the steps taken to get K back.
I wish it had been saved for the film itself, not the trailer. It was just too much. I know it will probably end up being a minor part of the film, but it still annoys me.
I wrote my first post immediately after seeing the trailer so I was fired up a little more, but I still feel the same way. I like to go into a movie knowing as little as possible and now I feel I know too much.