This is the part you are missing.
No part of the aura rules, either on page 6 or in the glossery state that attacks created from an aura are not attacks. So there IS NO SPECIFIC RULE trumping the general rule.
Bravura Warlords have a passive ability that can permit an extra attack when someone uses an action point and hits with an attack. That extra attack is, in fact, an attack.
A Barbarian has a passive ability that permits an extra attack when they critical hit. That extra attack is, in fact, an attack.
Aboleth lashers have a passive ability that permits an extra attack when they have combat advantage. That extra attack is, in fact, an attack.
The fact you're calling it an attack.... it cannot simultaneously be an attack and not be an attack. That doesn't make sense, and has no rules support in the game.