Technically, all deep dungeon content will eventually be killed after Duty Support is out since people usually do Deep Dungeon runs for faster DPS queues to get EXP.
I've noticed less and less people were doing PoTD ever since ARR had story mode. I will expect the same to happen to HoH once SE decides to implement Duty Support for Stormblood.
And by that time, new players will definitely be a lot more anti-social since their first interaction with other players in dungeons start much later. I wouldn't be surprised if it backfires on the community in the long run.