"Music That Glows In The Dark"
If you look in the kickstarter updates there is information about how the games plays with 2.
So, no it shouldn't say 3+.
CORRECTION: The update is not particularly about playing with 2, it is about how you can be successful without negotiation. I think that would cover the case where your opponent chooses not to negotiate.
When it first launched the designers said it wouldn't work well with two.. Maybe they changed it but still my opinion stands until proven otherwise. Too many times people slap 2+ on the box but the game really needs more.
EDIT: I just went through all the updates, don't' see any mention to the two player game. Honestly it really doesn't seem like it was thought out well or tested. How can negotiation with two ever work?