GW2 really doesn't need vanilla servers as all of the content in gw2 remains relevant and gives appropriate loot by design.
When you compare it with other mmo's like WoW which have vanilla server, it makes sense in that game because every new expansion make the old content and maps completely irrelevant except maybe leveling. A World boss in WoW which required 40+ players to kill can be 1 shot by characters couple expansions later, this doesn't happen in gw2. Can you solo claw of jormag? I don't think so, all of the world bosses and meta events are already run regularly exceptions being the one's which aren't pugable (triple trouble for example).
Besides, there is no one forcing you to play elite specs, some vanilla specs are totally viable and still run regularly. Example being the vanilla support bunker guardian is currently meta in pvp.