They should implement a husk of the pit style system for all exotics and raid legendarily guns. This gives you an option to level up guns farther when you get a special item, or new content comes out. Maybe this just adds additional damage nodes. Maybe this re-rolls the weapon with new perks befitting the new level. Whatever the system just let us keep the raid and exotic guns we like. Otherwise they need to have viable replacements for all the existing guns. The Crota's end guns thus far don't do that for the vault of glass. And there are no where near enough exotics to replace the current set.