Hi there, let me explain you that tier better:
The wish consists in like you said, ask for a fetish or other two options like the NPC or the item to be add into the game.
But that is not a full scene or the decision about whose characters will interact in a scene, or the decision about how the history will turn into.
Is more like... you tell me the fetish (in the case you take that option) and before you make the pledge I will tell you if that fetish is forbiden or not and if that fetish can fit in the upcoming scene or if the fetish can be added in a upcoming version.
Also the current guy with that pledge is only pledging because he wants to support this project but until now he only have requested one NPC to be added in the game in a future version.
So, your answer to if this is my game... yes it is, and always will be!