I know i am wrong but...
January New Super Mario Bros U
February Nothing
March Yoshi's Crafted World
April Daemon X Machina
May Fire Emblem Three Houses
June Town
July Nothing
August Animal Crossing
September something uannounced or Nothing
October Luigi's Mansion 3
November Pokemon
December Nothing

January: New Super Mario Bros. U / Travis
February: Something unannounced (one or more of those big retro Final Fantasy titles)
March: Fire Emblem
April: Something unannounced (Labo, Pikmin 4)
May: Yoshi
June: Animal Crossing
July: Town
August: Something unannounced (another Wii U port, maybe Zelda Wind Waker)
September: Daemon X Machina
October: Luigi's Mansion 3
November: Pokemon
December: another big unannounced holiday title (Metroid Prime 4 / Bayonetta 3)

Super Mario Maker 2, Yo-Kai Watch 4 and a 2D Zelda should come in 2020.

SMT V might come out late next year in Japan. Metroid Prime 4 will be out second half next year. Animal crossing is before July. Luigi's mansion is October. Fire Emblem is May.

We will probably see some third party (Japanese) exclusives and Nintendo certainly has a few aces up his sleeve. In 2019 we will see about 14-18 exclusive AAA games for Switch.

In 2018 were 17 AAA exclusives Switch games (including ports and Labo):
1. Bayonetta 2
2. Kirby Star Allies
3. Nintendo Labo: Toycon 01 Variety Kit
4. Nintendo Labo: Toycon 02 Robot Kit
5. Donkey Kong Country: Tropical Freeze
6. Hyrule Warriors: Definitive Edition
7. Mario Tennis Aces
8. Captain Toad: Treasure Tracker
9. Octopath Traveler
10. Monster Hunter Generations Ultimate
11. Nintendo Labo: Toycon 03 Vehicle Kit
12. Xenoblade Chronicles 2: Torna ~ The Golden Country
13. Super Mario Party
14. The World Ends with You: Final Remix
15. Pokemon: Let's Go
16. Sid Meier's Civilization VI (console ex)
17. Super Smash Bros. Ultimate

Next year for sure will be better (maybe not in quantity, but in quality - more new games, less ports).

Exclusive as in Nintendo / Console exclusive as I go on... Obviously a ton of guesses along the way, but all are confirmed to be releasing. Wont guess on games not yet revealed :P I do think we're going to see a couple of remasters to round out the lineup and another not yet confirmed new game or so from Nintendo (Retro Studios? :I) And possibly another exclusive from either Ubisoft or Square Enix.

January: NSMBU DX, Travis Strikes Again
February: Grandia I+II HD remasters, Metroid Prime Trilogy
March:
April: Yoshi: Crafted World
May: Fire Emblem: Three Houses
June: Welcome to Animal Crossing
July: Daemon X Machina, Town
August: Luigis Mansion 3, Windjammers 2
September: Yokai Watch 4
October: Shin Megami Tensei V
November: Pokemon
December: Metroid Prime 4

I'll just predict that Metroid and Bayonetta are coming out before SMT V.

50/50 on SMT V being a thing and it wasn't transformed into dollar store Persona.

I'm sad the Yoshi game is not going to be called Yoshi's Flipping Island :(

Given how Nintendo's been recently, I am pretty sure that we are going to see at least one unexpected release.

"Oh hey it's a Nintendo Direct.....Star Tropics?"

For a random example. Frankly it could easily just be some new version of Duck Hunt doing a Kid Icarus Uprising on itself.

Both of those are so niche I don’t think they’ll make a dent in Switch sales. Even Mario Party was a more significant release.

Funny, because the gameplay that the new God of War featured used to be considered "niche" not long ago as well.  Remind me, how did that one sell?