8 Players dungeon
The purpose of removing the typical trinity from the game was to negate people from sitting around for hours trying to find someone of a specific profession and level to party with. This would cause that issue so there is no way they would consider it I’m afraid.
I think a dungeon which needed every class would not be good since it would complicate the group play again.
But I fully agree that you should be able do have bigger groups for dungeons… I don’t know how hard it would be to implement but since there is allready scaling in the open world perhaps dungeons could scale in between 5-9 players. That would be a great addition in my opinion since then you could really sometimes do a dungeon with all your friends / guildmates without someone left out since it happens quite often that you are not exactly 5 / 10 / etc people and of course you can just take randoms but once in a while just playing an evening with friends where you don’t have to rely on strangers for having fun would be nice.