Folks expected the Nintendo Switch to get Monster Hunter, but the question was "which version?" Today, Capcom has announced Monster Hunter XX for Nintendo Switch. MH XX is an expanded version of Monster Hunter X (Monster Hunter Generations) for Nintendo 3DS, which launched in Japan on March 18, 2017. There's been no word of a Western release for Monster Hunter XX yet, in either version.
Further details on the game will be coming during Monster Hunter Championship 2017 in Sapporo, Japan on May 27, 2017. There will be a livestream of the event at the link above.