The key to keep player interest in Destiny is to allow Guardians choose their own weapons. Everyone has a different choice surely and a gun they admire. Forcing us to depart with the guns we loved to play with is not a wise thing to do. I still want to use my Fatebringer and VoC with the new raid , in fact i still use only those guns and ignore all the other vanguard guns ( have plenty upgraded to 331 ) but none take my attention. Surely i am interested on the new Raid primaries. However let us consider which guns we want to use and keep Vault of Glass guns and the Raid relevant with the game. As we can see from Husk of the pit , Destiny has ability to easily add Upgrade option to any gun they prefer , so don't miss this opportunity and implement the upgrade option.