Star Fox tends to launch at the end of a console’s life… so there’s that maybe.
Sakurai has been up to something… probably the next Smash, but I can always dream it’s a new or even remade Kid Icarus.
And probably some last minute WiiU ports.
Metroid Prime 4 is probably too high profile to leave to the switch… (and Mario hasn’t had a launch title since the N64, maybe GCN at a stretch) but they could always pull a Twilight Princess I suppose.