we have already blurred the difference between primary and secondary to the point that its arbitrary. for example we have primaries that use ammo, and have explosive tipped ammo. doesn't seem like now is the time to draw hard lines between what makes a secondary weapon secondary and a primary primary.
the way i have always understood it is that primary weapons are the first choice weapons that you use most of the time, and secondaries are the weapons that you use at an appropriate time when you need a specific tool for the job at hand. if you follow military history there was a time when we considered guns on a fighter were obsolete, and made missiles the primary weapon, eliminating the gun entirely. of course there are situations where guns are appropriate, so we made an add-on pod as a secondary option. then we re-integrated the gun back into the aircraft in later fighters, yet still considered it a secondary option. guns in modern fighter jets are still considered a secondary weapon. of course then you have a jet like the a-10 where the gun is once again primary. a modern mobile artillery piece can fire guided ammo as well, the main gun being in essence a primary weapon, say it also has a machine gun turret for defense, it would be the secondary weapon.
i dont really see any harm in blurring the lines further so long as it doesn't break anything. it would definitely ensure that we never get bored with the weapon configurations we can come up with by mixing and matching different weapon features.