In the description of the regional Prophecy teaser trailers on YouTube there is a line at the bottom which says "Dungeon only available during Season of Arrivals". This means this endgame Dungeon which is free for all players will disappear in 3 months time.
It's an incredible piece of content and doesn't deserve to disappear like the Sundial, Vex Offensive or Seraph Towers, this is a timeless activity and is leagues ahead of any other seasonal activity.
Please reconsider your stance, I feel a lot of the community would agree.
For reference - https://www.youtube.com/watch?v=_9-f1trGiIY