No way this or any other party game will come close to 8 million in sales like Mario Party.
This isn't the first minigame collection that Hudson has released post-Mario Party, they've also released some generic 100 minigame collection in Japan, among other games. Some of their would-be Mario Party minigames have also been turned into WiiWare titles. I think the reason Hudson doesn't do another Mario Party is that they don't get a cut of the game's sales, and instead are paid one lump sum to develop the game and that's all. Hudson gets 100% of the revenue of all games they develop and publish themselves, so even though games like this probably won't sell more than a few ten thousand units, it might still be more profitable than creating Mario Party games.