It's almost guaranteed to be a 1-1 trade in the early stages of the game. Bomb Lobber was a solid enough card to see some play in GvG control decks, and this is significantly better costed and has elemental synergy for Thunder Lizard or Tol'vir Stoneshaper. It's not too important to be auto-include, but it means shaman has even more early game control options.
Played a few games of Quest Priest and Volatile Elemental has done serious work! Playing it with Spiritsinger Umbra is just awesome! Not to mention making copies with Mirage Caller, Barnes, or Onyx Bishop. I played 6 of them in my last game and got the deathrattle effect twcie on 3 of them. So much value packed into such a small card!
This card is in my opinion super underrated along with Sated Threshadon. Strong Deathrattles have been lost in the standard rotation and this is a good early-mid card to stabilize the board, the effect can be controlled to a certain extent and its 1/1 body is great in getting things like divine shield or a swarm of early pressure off the board. It can be played as a cheap enabler for Priest Quest and is super solid in general. Give it a try at least before judging it.