"A peaceful new life on a deserted island awaits....
#AnimalCrossing: New Horizons comes to #NintendoSwitch on 20/03/2020!"
"Start a new life with the Nook Inc. Deserted Island Getaway Package and enjoy a peaceful existence full of creativity, fun, freedom and charm when #AnimalCrossing: New Horizons for #NintendoSwitch arrives March 20, 2020."
@Nintendo tweeted (translated):
"A new life starting on an uninhabited island. Nintendo Switch “Atsumaru Animal Crossing” will be released on March 20, 2020. #NintendoDirectJP"
I'm not sure whether the smaller divisions, like Nintendo of Russia, will release later or not. But the largest 3 markets for Nintendo are all a March 20th launch.
Yeah, ever since Pokèmon X and Y in October 2013 Nintendo has almost always released their big games on the same day worldwide. This will be the first such main-series AC game, though (although City Folk released in North America, Europe, and Japan within a couple weeks of each other).