A screen for games in the back is totally unnecessary, I'm assuming it'll only play games from the Tesla arcade.
If there is kids in the back then they'll be on their phones, Nintendo Switch, iPad's etc and won't bother with this gimmick.
Instead of a rear screen how about that part of the accounting budget go towards 360 parking cameras......and stalks.
The rear screen makes sense for climate, radio and seat heater controls. Especially since it has 3 zone heating.