Quote Originally Posted by GentlemanVoodoo View Post
By RAW, it would not apply. Sneak Attack does clearly state that an attack roll of some sort is required. Even the secondary part that states, "You don't need advantage on the attack roll if another enemy of the target is within 5 feet of it, that enemy isn't incapacitated, and you don't have disadvantage on the attack roll." has it. Piercing Arrow is a Dex Save for damage ability and doesn't require an attack roll. So in the most literal text of the rules the answer is no.
I have to point out it require an attack, not an attack roll.
I can see it why it can be understood like this(the text use the following words:"if you have advantage on the attack roll. "
But it look like a specific rule for me.

We have to known options for attacks with no attack rolls(grapple and shove) but for now we have no finesse or range weapon I know about that can be used for those attacks.