The Cursed Shard

On the PTR, it said that you get 10x Wakening Essences for turning this in, but on live the reward is removed. You do get 20x Wakening Essences from just opening up your Mythic+ chest even if that's the first thing you do upon logging in after patch day.

[item=154880] > this quest (optional) > A Titanic Effort > [currency=1533] > [item=154879] > repeat with A Titanic Effort

It seems you can start collecting Wakening Essences before you get to A Titanic Effort - I already had four.

This is an optional quest. The only purpose of it is to lead you to Arcanomancer Vridiel, who will then give you A Titanic Effort.

As of live: you do NOT get essences when handing this in. It's not a bug, you didn't do it wrong, it's just not meant to be there.

However...
You do tend to get 5 essences at the same time as picking up the Cursed Shard that starts the quest, so you will already have something.

I got my shard and essences as additional rewards for my first random heroic of the day. Others have got it in their emissary loot bags. It appears to be that the game wants you to get it, so I'm sure there are other sources no matter your flavour of game. But all of us got 1 Cursed Shard and 5 Wakening Essence (note that the latter is a currency, so it won't show in your bags, again do not panic!).