The official Pokémon movie website has updated. Translations follow:

The 20th Anniversary Pokémon Movie Will Have Its World Premiere in Paris!

It has been decided that "Pocket Monsters the Movie: I Choose You!" will have its world premiere at Japan Expo,
which will be held in Paris, France this summer.
This was announced at the "Japan Expo 2017" press conference.
(In the photo, from left to right: Pikachu, Japan Expo CEO Tom Sirdey, "Anime 100" honorary advisor Masao Maruyama, Japan Expo official reporter UMI☆KUUN)


For further information, see the official Japan Expo website.

Source: http://www.pokemon-movie.jp/news/?p=2569