The official Pokémon movie website has updated. Translations follow:

Media Information

Magazines:
Saturday April 27th: "flowers" - Information on the pre-screening
Sunday April 28th: "Mebae" - Information on the pre-screening
Tuesday April 30th: "TV-kun" - Information on the pre-screening
Tuesday April 30th: "Baby Book" - Information on the pre-screening
Tuesday April 30th: "First Grader Magazine" - Information on the pre-screening
Tuesday April 30th: "Pucchigumi" - Information on the pre-screening
Wednesday May 1st: "Kindergartener Magazine" - Information on the pre-screening
Wednesday May 1st: "Cíao" - Information on the pre-screening
Thursday May 2nd: "Sho-Comi" - Information on the pre-screening
Wednesday May 8th: "Petit Comic" - Information on the pre-screening
Thursday May 9th: "Serai" - Information on the pre-screening
Thursday May 9th: "BE-PAL" - Information on the pre-screening
Friday May 10th: "Big Comic Superior" - Information on the pre-screening
Saturday May 11th: "Monthly Shonen Sunday" - Information on the pre-screening

*Note that these are the scheduled publication dates, and as such are subject to change without notice.

Source: https://www.pokemon-movie.jp/news/?p=3631