According to the official twitter , the reason is the ongoing work on the full-length anime, so that the picture presented was their best creation.
The Japanese premiere will be held July 19 at 9 am, it will mark the simultaneous start of sessions in 359 cinemas. There will also be organized shows in IMAX format.
According to available information, the film will appear in the Russian box office. No release date or distributor has been announced.