The official Pokémon movie website has updated. Translations follow:
Media Information
Wednesday June 26th: "TV Tokyo Music Festival" on TV Tokyo - Theme song performance (Sachiko Kobayashi and Shoko Nakagawa)
*Note that these are the scheduled publication dates/air dates, and as such are subject to change without notice.
*Broadcast dates will vary depending on where you live. (some areas exempt)
For details, please see the website of your local TV station.
Source:
https://www.pokemon-movie.jp/news/?p=3678