Known Nintendo insider and blogger Emily Rogers has stated on the Reset Era forums that she’s aware Nintendo has two unannounced Wii U ports in development for the Nintendo Switch. You can guess which they are. She also says in the same thread that Nintendo will be focussing on Animal Crossing: New Horizons this first quarter. That could mean the traditional start of year Direct could be an Animal Crossing focussed blowout.
I can also confirm that Nintendo has (at least) two more unannounced Wii U ports. They are not difficult to guess because there aren’t many Wii U games left to port.