Not needed. Some of the vault weapons at 300 are still superior to vendor bought 331s already. Besides, are you not able to do nightfalls or beat crota with these weapons? The difference being is that with revenge, timepiece, fate bringer, etc... They were all geared towards doing the nightfalls. And I can't begin to tell you how many of these easy roller crota players struggle to do basic nightfalls still, namely because they don't have the very very useful arsenal from Vault.