This is related to the question thread
Dungeon Spawn Rate. Where as that thread is a question on spawn rates, this one is more of a discussion on a potential approach that the game could take with dungeons.
Traditional approaches to open world content isn't very well suited for open world dungeons. Usually MMORPG games will have a world boss spawns and do no world dungeons at all. Why bother create an obstacle that players could just camp or log out at to check for a respawn? This kind of leaves Ashes of Creation in an experimental position. Another game that I feel was rather experimental with open world content is the game Guild Wars 2, particularly Guild Wars 2: Heart of Thorns. They had several zones throughout the world added in that expansion. Each one had their own unique approach to world bosses. One of those zones was like a traditional instanced dungeon, but open world in the context of how the game treated open world content.
Dragon's Stand is a zone where all players are rounded up in a single camp, waiting for their opportunity to strike the stronghold of an elder dragon. When that opportunity comes, because enough time has passed and enough players are present to trigger the opening event, the next step begins. Three lanes open up. Each lane requires enough players to participate in, so that the defenses of the final boss are weakened. Once weakened, all players in the zone then meet up at the final boss to defeat them. After the boss is defeated, players have a little bit of time to gather all of their rewards, talk with NPCs and get out of the zone before it needs to close. People cannot spawn camp this boss and players must work together from start to finish to reach their goals. All obstacles, including the sieged gates that were blown up, get reset for the next time players wished to encounter it.
This is basically how a normal dungeon and raid instances work in many MMORPGs today, but it allows for all players to join in. Players start at the entrance, end at the final boss, and eventually the dungeon gets reset. Would something along the lines of this approach work for AoC if it had a longer reset timer?