I'd love for there to be a way to give players the darkness effect without summoning the warden to create spooky atmosphere in our builds in survival mode. Many players want more ways to create darkness in our builds. There's new ways to do that since caves and cliffs, but having darkness would take it a step up. Even better if it's activated by noise/vibration much like the new skulk blocks already are.
Having a block be activated to give the player darkness I think would be more interesting than something like a potion especially, not only does it keep darkness as an effect tied to skulk, but it allows for a different "kind" of trap. There's creative potential there I believe, as survival players could choose to make it avoidable in their builds, or create a way to force players to trigger it in their builds if they so wish.