I didn't get to see the TNT live myself but during it you may have heard about some people talking about something called the Command Board and how it is similar to Fortune Street.
In Kingdom Hearts: Birth by Sleep for the PSP, the Command Board is a minigame designed to help your abilities level up. The gameplay is to what you saw in Fortune Street but it is much simpler. Some things like: owning two properties next to each other increasing their value, leveling up properties, Buying people out of properties, going to all four checkpoints then heading to the start netting you a bonus, and separating the cash you have to spend from the overall cash you have; are part of both.
I haven't yet finished watching the TNT yet, but from what I have seen so far the main difference is that the board in Kingdom Hearts is not divided into different areas like Fortune Street is and thus you do not buy stocks in an area. Also, while it is more an astatic change, in Kingdom Hearts you are buying spells and abilities rather then the shops of Fortune Street.
Here is a video showing what the Command Board from Birth by Sleep is like, if you want to compare the two (video was not done by me so sorry about the resolution, remember PSP game):