User blog comment:The Demon Archer/Any Possibilities that Cobalt Blue might arrive./@comment-76.78.130.65-20151105201910/@comment-24901406-20151105211210

It's been confirmed that's what it was intended to reference by Grant Gustin. I'd take that as pretty good confirmation that it's what they were intending to do at least. Of course plans can change and it can be fitted into a new plot line, but at the time of filming it was intended to reference that story.