Twitter user Pixelpar is claiming a November/December release date for Pokemon Switch. Yes, that seems like an obvious bet (assuming the game is still on track for 2018), but they've also claimed that Pokemon Switch began localization in February of this year:
For anyone wondering, Pokémon Switch materials have been undergoing localization since late Feb (possibly earlier).
I've already had confirmation that it's targeting a 2018 release. Educated guess (based on previous Pokémon localization timing) it should be ready for Nov/Dec
— Pixelpar (@pixelpar) April 13, 2018