At this point, it appears likely to be a plot device...but as to how it will be used, that is not at all clear. Well, it's probably going to stab someone, but who, when, where, and why are still up for debate. I know which aorta I would prefer it gets plunged into, but don't assume that I'm necessarily going to get what I expect. If this were real life, I'd yell 'Occams Razor!' and say we know where it's probably going, but we are talking about writers here; I trust that group of plot-twist-loving mongrels about as far as I can throw them when it comes to foreshadowing!