The official Pokémon movie website has updated. Translations follow:

A Pokémon Stage Show will be Held at the Takara Tomy Booth at the Tokyo Toy Show 2017 Sunday June 4th!

We will hold a stage show where Satoshi and Pikachu will appear! There will be lots of info on Pokémon toys, the TV anime and the movie!
We've also invited Rica Matsumoto as a guest, so she'll be holding a concert there!

Time and date: Sunday June 4th from 12:00pm and on
Location: The Takara Tomy Booth, East Hall 1, Tokyo Big Sight
Content: A Pokémon stage show



Source: http://www.pokemon-movie.jp/news/?p=2681