I know this is going to sound like Sunsetting talk but the truth is I do not think we can really curb stop certain enemy factions any more than we already have. This mainly is related to the Vex and how we over the course of the franchise have dismantled KEY minds to the vex collective, the vex offensive failed, and the undying mind is dead, and with the loss of the infinite forest Id say they are on their last legs, this being the vault of glass and Quria blade transform, Now Bungie noted that the Vault of Glass was getting a facelift as well as some changes, but what if The vault returns as a taken raid with Quria as the final boss? The reason for Quria being there is to be a catalyst to Take what remains of the vex collective, similar to what was seen on Io for the Man of War quest. Perhaps after the defeat of Quria, The collective will truly crumble and thus truly defeating an enemy faction for good and then making room for something new. However this logic can also be applied to the Eliksni and the Cabal as well as they are being set up as potential allies through the house of light and an uneasy alliance with the remnants of the cabal as they will be willing to work with us to fight the bigger threat, The hive and the darkness, and whatever race may be related to it. This way when we eventually defeat Savathun and Xivu Arath in the coming months, there will really be nothing else left to really fight other than the manifestation of the Winnower and the Darkness. We have been fighting the good fight against these guys for years, But the fight must eventually come to the end... and frankly, I am not the biggest fan of the vex and id happy to really see them beaten once and for all and to beat them where all their bs began? Oh, that would be SO satisfying.