It's BADLY needed. People are running full-inventory characters, one-out one-in on their vaults, and with half-full postmasters.
You added a dozen new armour sets across all 3 class-types in Rise of Iron alone... where do you expect people to put it? Personally, I haven't even opened the Iron Armour set from the Rise of Iron record book because there's nowhere to put it. How crazy is that? One of the main rewards for Rise of Iron and I can't even open it.
Vault Space, Vault Space, Vault Space, Vault Space, Vault Space.
Just to be clear, we need vault space.
Kiosks - These are an alternative and one you could utilise to help clear out vault space. Specifically Raid gear. Make a Raid gear kiosk and set it so that any gear we gain in a raid becomes available at the kiosk at the light level we currently are. To prevent people spamming it for max level gear, you could make kiosk Raid gear unable to be infused into another gear piece.
Either way, we NEED space BADLY.
At the very least, tell us if we are or are not ever going to gain more vault space. At least that way we know where we stand, and can then start making decisions on whether we keep stuff or have to start the brutal process of deleting hard-won, long coveted, no-longer-available gear.