People have been talking about "Miyamoto's new IP" for the last 15 years, lol. The funniest part is at E3 2003 when a lot of people hyped themselves up over a rumors of the new Miyamoto IP and it turned out to be Pac-Man VS. Then you had the Wii Music debacle in 2008.
Miyamoto is the head of the entire software development division at EAD. He doesn't just work on one game. Every Nintendo game virtually involves Miyamoto in some way.