Changing the cover art on the Kickstarter page didn't effect any of the rewards (there was no reason to assume the retail box would use exactly the same artwork as the Kickstarter).
It is not that easy to just change an actual reward that people have already pledged for. Kickstarter doesn't allow editing the tier descriptions, at least in part so that there is no appearance of fraud with rewards being changed after the fact. There are certainly ways to change rewards when required, but to even clarify something or add rewards, you basically need to make the current tier limited and add a duplicate with the updated description.
Even if nobody pledged specifically for the Ouija board, and nobody had any objection to that reward being changed, the process of determining that and making it happen would be neither quick nor easy.
As still would not mind if you guys open a new tier without the board. Maybe enough people upgrade to that you guys can make sure that the cloth map is not as bad as last time :p
