This is not going to happen.I could see another album like Xscape coming in the near future- GYWOOM, Chicago 1945, Dream Away, I Was The Loser, TYLA, What You Do To Me, maybe a few tracks from the canceled Dangerous special edition. There’s definitely enough unreleased material for at least one more album.
Sony Music's chief executive Rob Stringer stated few years ago that there are actually no plans to release any more full-fledged, posthumous albums (like, 'Michael' and 'Xscape').
The strategy is to release new, stand-alone songs on a one-off basis, because we live in a streaming and track-based world.
Also, Rob Stringer implied that Michael Jackson anniversary albums are not affected by this, and they will continue to get a release (as proved by the release of the 'Thriller 40' anniversary album).