My memory had placed several other bosses in my brain from when I played the 3DS version. They weren’t in the Wii U one, so I suspect my mind was playing tricks. Or I was getting confused with something else (god knows what though). Or they were optional and I somehow avoided them? It’s a mystery.
Pretty sure I finished this in a slightly shorter time than on the 3DS too, although that was to be expected. It was still a lot of fun, and I’m glad I played it again (and it was over a year since I last did anyway), but there’s really no difference – phantom bosses notwithstanding – between the Wii U and 3DS versions.