One thing I could see them doing to make vog relevant is make the drop pools offer 331 attack weapons. You can still obtain faction weapons with 331 attack, but not able to upgrade them from 300 to 331 with what you previously owned. If anything u could see them offering higher attack legendary gear but only offering them from a possible higher difficulty vog. Either way considering the current method of upgrading exotics and the fact that they do not offer to upgrade any legendary gear, I'm sure they didn't intend on offering upgraded versions. In my personal opinion they should not have sold 31 and up armor and weapons it should have been earned from the vault, and each expansion should offer the next logical step in upgrades.