I suppose they were afraid that if you assembled the puzzle and learned about the spoiler, then you'd sue them.
On the spoiler topic, I have a love-hate relationship with them. On the one hand, I like little spoilers about my shows. Enough to intrigue me, but not enough to ruin the whole thing. So I wonder how much insight this puzzle gives to Lost. How about one of you assembles it and lets me know if it ruins everything?