Can you add halo waypoint back to Xbox so we can get all the armour and stuff off of it
Unlikely.
Read the FAQ pinned for any further questions regarding Waypoint Armour.
Waypoint is still on Xbox. Though, you can only access the Halo Waypoint App on the Xbox 360. You can only unlock all the armors on the 360 Waypoint App. After you have done that, then you can download them from the Xbox store on Xbox One for backwards compatibility play. But like James has said, there is a thread pinned to the top of the forum with all the information pertaining to getting all these armors and more.
that sucks