The cast of the first three seasons will return to reprise their roles for the upcoming final season. Lastly, a compilation film titled Attack on Titan: Chronicle will have a limited theatrical run on July 17th and will summarize the events of the first three seasons.
Attack on Titan: The Final Season was originally announced for a 2020 release on NHK General. But after the unveiling of this season's details, the release date for the season is no longer listed.
[Source: Anime News Network]