Sure the car will come out less damaged, but the pedestrians will be far more likely to die.
There are aluminum vehicles that weigh more, it's really momentum rather than gross weight
Or, to put it another way, can a soft body deform around the vehicle and be thrown away from the impact? The sharp wedge shape from the front grille to the hood kinda says "No" to me.
Regardless, it will be good to see what comes out of testing.
Once again today i'll be fair to Elon, most new US SUV/pickups don't pass EU crash tests.