Environmental issues: this is an excellent idea, for reducing the amount of atmospheric and noise pollution on the ground. Admittedly, there'd still be the pollution caused by the APU, which tend to make rather more noise nuisance due to their higher position and 'pink' noise signature.
You'd probably still want a headset person to monitor pushback and engine start, unless you went for a more sophisticated camera system. This has long been advocated for monitoring the exterior - the Royal Aircraft Establishment at Bedford, England had a setup fitted to a BAC 1-11 twenty-odd years ago. It could now find that its time has arrived.
This could change the face of aircraft ground handling. No more 'sorry, Ground, we'll have to cancel our pushback, our tug hasn't arrived!'
Cheers,
The Odd One