I don't think VoG will irrelevant long. They're probably up the difficulty level after a certain period of time so you can run it on level 32 then 40 or whatever the next cap will be. And Bungie has stated that we haven't seen all the Vault has to offer. I wouldn't be surprised if they add an additional mini boss or path (probably wishful thinking! But a girl can dream). It's just not a change I see being made until later.