This seems like a refrence to the changes made while repairing the damage from the first torpedo.
They rolled a modernization into it and this upgrade appears to be principally what her Kai form represents in game. Along with replacing the eight inch guns, trimming the super structure, and adding more sensors and light AA they did in fact bulge the hull, although unusually it was an asymmetrical bulge to help offset the superstructures weight. (previously a certain amount of fuel was left in the tanks as ballast for this, after the bulging the entire supply was available which also resulted in an effective increase in operational range)
