About some Destroyed NLC quests

I doubt it's going away. I predict they will leave the existing warp in the mirror to get to Destroyed NLC. I think they will just just make a portal in town to go back to old NLC, which will also connect to old Crimsonwood. This would be the easiest path since it requires no changes to the existing map structure and all they need to do is make 1 portal. (The other option is to add old NLC to the mirror, but that's not really necessary if they simply put a door in Destroyed NLC.)