Weekly Famitsu Issue No. 1695, due out on May 27, has a 14-page feature on the announcement, formerly known as Project Stella, including interviews with key staff. Only the front cover of the issue has been published online, so details including platforms, release date, and gameplay information are currently unknown.
The official Twitter account for Relayer is available at @Relayer_SRPG. A formal announcement is coming soon.
Outside of the Relayer announcement, Weekly Famitsu also has features on the 35th anniversary of Dragon Quest and 30th anniversary of Metal Max, as well as the latest information on The Caligula Effect 2, Monster Hunter Stories 2: Wings of Ruin, Utawarerumono: ZAN 2, Senran Nin Nin Ninja Taisen Neptune: Shoujo-tachi no Kyouen, and The Legend of Heroes: Kuro no Kiseki.