Btw, idk if this still works or not, but it used to be a thing that when you upgraded the EA to necro, it removed it from your active hand. In other words, if you have no other primary weapons with you when you upgrade it, you can "permanently" disarm your primary (assuming you never pick up another, as it will auto equip). I think there was more that went with it too, something along the lines of special ammo showing more or primary ammo restoring special, but i think that got fixed.
Yeah I remember that it was pretty cool. I think the catch is that you can't have any primaries in your inventory, and you also have to have another exotic weapon equipped.