From what I saw over the last week, Pagos is still super active. People are still running NM trains, spawning louhi, and there's always a light farm or two to join.
I had to get a couple of crystals from Anemos (the first zone) too and noticed that was kinda dead though. There's a chance I was just a bit unlucky but I kept being put into instances with 3-10 people in them all day. In a way it kinda offered me a glimpse of how difficult this stuff is gonna be once the expansion hits and the trains go away. Can you imagine trying to spawn NMs and farm light all by yourself in a year's time? Nevertheless traversing these zones while under-levelled and without a mount. Sure everything scales to the player count but I predict it's gonna be extremely rough and time consuming.
Best to get it over with now