The people who know are not saying anything. The people who are saying things, don't know.
IF this is a missile, then there are very few possibilities. Either: We screwed up and sent something up we should not have. Or, We sent a message to someone. Or, Someone sent a message to us.
If this was a mistake, then usually the news gets it out in pretty short order. The fact that there is a dearth of reporting lends credence to the theory that this was intentional.
If this was intentional, then the symbolism is pretty stark. The real question is this: Whose message is being sent, and to whom? Only time will tell.