Did they merge? Got renamed? Am I remembering wrong?
We have never had a board dedicated to World Building. but I do have a core-memory coming up that we my have had a General Crafting board, that was like a art+games making version of general interests?
Im not sure what happened to that one, I guess it got renamed and split (maybe Art Crafting has a lot of it). My usual approach to board creation is to look at what people are creating on various boards and then see if there are any threads following a trend that might be better grouped together while not making the number of boards overwhelming.
World building would definitely be in the overall ballpark for this forum, it really depends if we have a critical mass of world building related topics that should be grouped!