You don't think Town or AC has a chance at a June release? They have Town, Luigi's Mansion 3, Animal Crossing and Pokemon left for big heavy hitters and I kind of doubt that all those would be the last half of the year with only 2 big games releasing in the first half.
There's a possibility for another big title for the 1st half if there's a January/early February Direct but I really think Nintendo is going to go hard in trying to turn Fire Emblem into a franchise that can carry a financial quarter due to the success of Fire Emblem Heroes. As for Nintendo's other heavy hitters, I can see Nintendo releasing Animal Crossing in July to carry the 2nd fiscal quarter like Splatoon 2 did in 2017 while using Luigi's Mansion 3, Pokemon and this year's Zelda game (I think it's a 2D Zelda title this year) to provide a holiday 1-2-3 punch like they did in 2018 with Super Mario Party, Pokemon and Smash.
One other title that I think can be released in the 1st half of the year is Daemon X Machina since it has already been shown at three events: E3, Gamescon and the September direct.