The official website for Sailor Moon Crystal has confirmed an announcement that was first made at the “25th Anniversary Usagi Birthday Event” (did you remember to send her a present? I bet you didn’t.). And that announcement is… the fourth season of the Sailor Moon reboot will be a two part theatrical movie event directed by Chiaki Kon.
The two movies will be covering the Dead Moon arc of the original story though no official release date was announced (those details will most certainly be revealed in the near future though so stay tuned to this website!).
If you need to catch up on all the happenings in the Sailor Moon-verse, the first three seasons are still available to watch on Hulu and Crunchyroll or, if you prefer, you can always pick up the first two seasons on home video via Viz Media.