There's a giant content gap in these areas. 

Elvia doesn't count. Elvia 2 in particular drops nothing, isn't worth attending, and generally is slow to grind to be worth the bother attending. Plus, every inch of it is solo. 

- I don't see why you can't understand there is only so much to be seen watching yourself batter something the same way you battered it the last billion times. Watching others do it is a chance to see classes you haven't played, might play, but currently don't play nor realize you would ever have an interest in. Simply, watching others IS a kind of entertainment.

Upper Gyfin is pretty good in this regard, but lower Gyfin is beyond the content gap. At least for my class. You don't go there o my class. Which means there's nothing for us to do we haven't already done. And no options (not enough places to go) from existing content. Making logging in feel like a chore to be completed until we cross the gap. Is BDO supposed to be chore?

Another way to look at this is... If you were dumb enough to make your Godr go to TRI you're stuck with it until you grind enough money to buy PEN. It won't enhance before you'd already there and beyond. Twice over in my experience. This isn't a cry for you to make Enhancing easier. The Enhancing experience SHOULD be this long. Just for the health of the game it should. We've learned that lesson from Western style games many times over. Don't go that route! However, it does demonstrate that there is a content drought. A very large one. 

As I said to a friend this morning when they said, "XYZ is gettiing borning," I replied instead, "Everything is getting boring," to which they simply replied "yep."

- This is where that endless dungeon idea you had would have fit in so well.

Why not make some sort of OSRIC style geomorph generator? (See below)
- Canonically you already have this in the game. The Sage built the construction sites for the ancient weapons to generate testing grounds for the weapons in just such a manner. The manga Realist Hero Saves the Kingdom (ignore the anime completely) also informs on this idea. Dungeons can be ecologies. 

- In this way, what you could do is make a Meteroid Prime style map. A single map.

- Each ecological region is solo.

- Players can enter and explore a lateral area.

- The areas are handcrafted by you in a rather quick slapdash using the map system below.
- The game then generates weekly some combination of these decorated differently depending on the ecological area they represent. 

- The creature types reflect those already in the game. A reuse of assets here wouldn't be an issue. 

- Let's say you have 7 ecologies: Green, Wet, Arid, Glacial/Sky, Underground, Lava, and Fantasy Mash.
- Next you spawn the maps using several large to medium style "plug and chug" pre-built terrains based on the map system below.

- After the plug and chug map tiles are built create distinct spawn points that are the same or slightly randomized each new week.

- the idea is that each week on server reset the game just swaps around the layout of the map.

- the map could be jungly since we haven't see that yet

- the idea would be to then keep it fairly flat and simple

- however, you can create all sorts of cooridors, choke points, and whatever else. like the Ascolonian Catacombs of Guild Wars 1. 

 - This would also give you a chance to show off your ability to create truly thematic content 

a) one area could be grassy like calpheon or belanos

b) another could be forested like treant

c) another could be Sycraia like 

d) another the winter region

e) another thornwood

etc

This way you can start the whole thing off as one giant "every level is represented" sort of thing. And the further you go out from the entrance in any direction the crazier and harder it gets. 

Simple stuff, easy to create, and no need to produce anything more than the initial generator, map tiles, and spawn points. Everything else is reuse. Which is to say most of it is reuse. You could even call it something like "Sage's Testing Grounds" and have it be part of the current dungeon mash up. Maybe even have dungeon cores in the center.  Please stay away from the puzzle type stuff though for this. This is more of "I want to fight something, but not the same crap I've been fighting every day - surprise me" sort of thing. Thus the ever changing nature of the place. 

Hmmmm..... fix the broken systems and classes that already exist... ORRR
Cater to the top 1% of players...
"Priorities"

" I don't see why you can't understand there is only so much to be seen watching yourself batter something the same way you battered it the last billion times. Watching others do it is a chance to see classes you haven't played, might play, but currently don't play nor realize you would ever have an interest in. Simply, watching others IS a kind of entertainment."

followed by

"- Each ecological region is solo."

What? Did your own plan derailed your own plan? :D

I don't want more content that rewards 1 caphras for 1 hour of play. I also, don't want the game to push too much into instanced content territory. That's just another flavour of snorefest, with the difference being mostly the geometrical shape you travel in.

More group content? sure! Add a brain to the mobs, eventually, maybe? I loved the group packs of GW1's Wind of Change, where the devs literally ripped the best PvE builds and taught their monsters to use them. Give a better reason to group up, other than melt the mobs faster. And cut the one-shot mechanics short. They're not as fun as they seem on paper. I sure hope that's what LoML will bring. Not just boss-like foes that just get spongier the bigger the party is and ultimately drop 1 beginner black stone (weapon) and a 10G gold bar for the effort.

Your idea ain't bad, tossing a random biome generator in Rux Maha Dekhima's stronghold, that can be accessed after the players have completed the actual dungeons that week. Lore-wise, it wouldn't work too well, knowing what happened there... best case scenario we'd find a lot of used condoms or something, not terrible foes, nor valuable treasures. But they could spin that around with the last biome and then slap your idea as a follow-up. It would still be nice to have it as an open space, though and, I'mma repeat myself, with smarter, not spongier mobs.