We'll know more in a week.
A loss of three solar masses in the merger would correspond to a power above 1046 W (probably much higher), the most powerful event we ever saw.
The combined luminosity of all stars in the observable universe is about 1049 W.
Is this equivalent to the annihilation of three solar masses worth of matter in an instant? Was such energy release predicted by present models of BH merger/collision or is this a new phenomenon?