Safe to assume it is a bug or oversight that only Energy weapons are dealing increased damage and creating additional special ammo instaed of all special ammo weapons. The TWID now states that "Special Surge currently doubles all second slot weapon damage and increases the chance of Special ammo drops in Portal activities" Not to mention we now generate special ammo on a meter, where does chance come into play? Does it just create ammo randomly or increase ammo generation? Second slot? You mean energy weapons? It's hard to tell the difference between bugs and misinterpretations now.