Bungie says Destiny silver appeared on Steam 'in error'

Earlier this week, Destiny Silver, the currency used in the game's microtransaction system, went up for sale on Steam. It was only there briefly before being removed, and purchases were automatically refunded later in the day. But an obvious question remained unanswered: What was it doing there in the first place? 

Bungie community manager David "DeeJ" Dague addressed the surprise silver on Twitter: 

But that doesn't really address the matter at hand, does it? As one user noted in a follow-up, "How do you sell microtransactions for a game that literally doesn't exist on PC?" To which DeeJ replied:

And that, so far, has been the end of it. But the mystery remains: Microtransactions aren't birds who occasionally fly into open windows, and especially not on platforms where the game they belong to doesn't actually exist. Which isn't to say that DeeJ's statement is inaccurate—I'm sure it's not—but what exactly is the "error" here?

Also interesting is the fact that while Destiny Silver is no longer purchasable on Steam, it's still listed in the SteamDB. I have once again reached out to Activision and Bungie for more information, and while I honestly don't expect a reply I will update if and when one is forthcoming.