Maybe some videogame studio is working in Birthright.
My opinion is Planescape can return before Dark Sun because it needs less work for the "crunch" part, and even it can be a compilation of adventures.
My homebred idea is Vecna created a "New Sigil", even bigger than the original, with "arcologies" ( = super-skykripper buildings) with a little noir-punk touch, and zones are more post-apocalyptic, but also used to farm or cultivate urban vegetable gardens. In this New Sigil the faction war continues, but more "private". And there are demiplanes used as "spin-off" to gathering recourses. There are a (intermitente and moving) planar gate between the two Sigil, and the lady of the pain allows this because it is in a dangerous zone within the "Maze", working practically as a mortal trap for intruders, and not always it is in the same place for a long time.
Planescape is perfect for a new line of Magic: the Gathering. It is "classic" D&D but also with a very different touch, far of the standard fantasy.
I would bet after Baldurs' Gate III and DLCs the next title will be a Planescape 2.