There are several possibilities as to what this could be, but Kid Icarus: Uprising would be my guess. Nintendo is likely going to be porting the 3DS library over to Switch the way they did Wii U. They’ve already started with Miitopia.

https://nintendoeverything.com/bandai-namco-contracted-by-nintendo-for-remaster-remake-of-a-3d-action-game/