Idk if it really feels more likely in April, May or June than March tbh.
March 2017- Breath of the Wild
March 2020- Animal Crossing New Horizons
March 2021- Monster Hunter Rise (with Super Mario 3D World+ Bowser's Fury in February)
March 2022- Kirby and the Forgotten Land.
Most critically acclaimed/big sellers of H1 came out in March during Switch era.
Meanwhile, April:
2017: MK8DX
2018: Labo
2019: nothing iirc?
2020: iirc nothing again
2021: ... Nothing?
2022: Nintendo Switch Sports
May gets even worse:
2017: nothing, minor 3rd party exclusives like Ultra Street Fighter II, ports like Disgaea 5 Complete
2018: Donkey Kong Country Tropical Freeze port, Hyrule Warriors Definitive Edition
2019: nothing iirc
2020: nothing
2021: Miitopia, Famicom Detective Club
2022: nothing
Meanwhile, June, being the second biggest month in a few years and the biggest in only one iirc:
2017: ARMS
2018: Mario Tennis Aces, Sushi Striker
2019: Super Mario Maker 2
2020: Clubhouse Games
2021: Mario Golf
2022: Fire Emblem Warriors Three Hopes and Mario Strikers Battle League
Going by scheduling strategies Nintendo has shown during all of Switch era, March seems like the most likely month. Specially for delayed games, Animal Crossing New Horizons was supposed to come in 2019, BotW in 2016, SM3DW+BF(February) supposed to come in holiday 2020, etc.