I feel like people are sleeping on the 3D Mario Remaster collection, Mario 3D World Switch, and a new Paper Mario game to carry them this holiday season. I think a remaster collection and Mario 3D World along with Paper Mario are big enough to carry the Switch this holiday. I know they're essentially just ports of older games but you need to realize that the Switch will likely be between 60-70Million by this Holiday, where most Switch games haven't experienced more obscure 3D Mario's like Sunshine and 3D World, so to them a remaster collection and 3D World are essentially new 3D Marios, and now with majority of Switch owners actually gamers unlike the Wii where it's install base was full of soccer moms, those 3D Mario games could be huge. Especially 3D world which is an amazing game that never sold well being on a system no one brought.
-Look at Mario Kart 8 Deluxe, despite being a essentially a port of a Wii U game, it's currently by far the bestselling game on the Switch and it's because most people who purchased a Switch never purchased a Wii U to experience Mario Kart 8, making it seem like a new Mario Kart game for people on the Switch. Also for the few Wii U owners who did have Mario Kart 8, they're inclined to by it a 2nd time on Switch for the extra content,portability advantage, and convenience. The same could happen for Mario 3D, it's a game most Switch owners haven't experience so to them it's a new multiplayer 3D Mario game, also there's rumored extra levels in the game, making people who already played the game more inclined to buy it a second time, especially with the Switch being a good portable multiplayer system.
-Along with the 3D Mario remaster trilogy with a new Paper Mario, Nintendo could legitimately get carried by those games this holiday.
-Other than that, I won't be surprised if we see at least some type of Pokemon game release this holiday cause at this point any game with the name "pokemon" slapped on it will sell, and Game Freak/Nintendo are known for milking the shit outta that franchise.
-BOTW 2 might be a possibility, however I'm not sure if Nintendo is willing to release it along with the multitude of Mario games in the same Holiday season. Nintendo might think the 3D Marios are enough for the Holiday and bank on it but we'll see.
-In my mind only possibilities I see for the big holiday title is the Mario games, BOTW 2, and/or some type of Pokemon remake/remaster