In the case of automatic car windows everything from ambient temps to battery voltage is used to detect if there's an obstacle present.
And I think what makes it kind of unacceptable is you can get off the shelf modules that integrate anti-pinch features:
https://www.continental-automotive.com/en-gl/Passenger-Cars/...
It wreaks of NIH syndrome or just trying to shave off some cost.
A quick search shows Teslas even have rear seat occupancy sensors, so that alone should disable the movement if there's a person detected in the back.