As seen on Autosport, the all wheel drive system discussed isnt the usual system where all power is sent the wheels via the engine. Instead, the system they had in mind is similar to what the Honda NSX have whereby a Kinetic Energy Recovery System is placed on the front axle, allowing energy to be recuperated and then deploy through the front wheels.
Advantages of this system include having more traction exiting corners while also potentially allow for the engineers to do away with the complex turbo-heat recovery system on the engine.
However, the teams are concerned that the measure would lead to an arms race. Haas team chief Gene Haas was quoted saying, "We have to be very careful before we say 'let's just throw a four-wheel drive car out there', because it could be another one of those ones where one team will probably hit a home-run and the rest of us will be struggling with trying to catch up with that."