They will never do this, because the DLC would be deemed useless. If you could run the V.O.G and obtain 331 weapons, it'd make the new raid less important. They should not make it to where you can obtain 331 weapons from the Vault. People are still running the Vault of Glass to obtain ascendant materials to upgrade their new legendary weapons/armor. People know that Xur has weapon upgrades, so people will still run it to obtain a possible free exotic as well. However, they should add a few items like the "Core of Atheon" to possibly upgrade your weapons to say, 318 or something; making the V.O.G useful for those that want to upgrade their old legendary weapons.