Just putting this out there, and I could be completely wrong so please keep in mind that this is just a thought -- we are literally a week into Witch Queen, and the raid hasn't dropped. Every expansion raid since Forsaken (Last Wish, Garden of Salvation, and Deep Stone Crypt) has led to some sort of World changes after its release/completion. Last Wish introduced our curse, Garden brought about the Vex Invasions, and DSC brought the Eclipse Zone and HVT's in the patrol space. Given Vow of the Disciple's direct connection to the Darkness/[spoiler]The Witness[/spoiler], and their influence on Mars through taking it away, and then returning it in its current state, its possible that the location hasn't been fully revealed yet. Vox Obscura takes place on planet, as well as The Arrival, so its possible that Mars is still on the way and just isn't open to us yet for story reasons. Again, this is just how I view it based on what's happened in the past. I could definitely be totally wrong so take it with a grain of salt...its just a possibility and I think that we should hold off on making judgements like this until after the raid. Witch Queen is already up there as one of the best expansions in Destiny history (if not the best), and I'm 100% confident that the raid will change things. I just don't know how...but given the scale of WQ, I'd bet it'll be more significant than something like the Vex Invasions.