So as of 7.3.5 Azeroth has a second moon and I am VERY surprised, unless I have missed it, that no one has mentioned it yet.
If it has been mentioned then whoops on opening a new topic.
Here is a video of them, new new moon is where Argus use to be, and if you are on a character that has killed Argus both the red star and this new blue moon are both in the sky at the same area.
https://www.twitch.tv/videos/219796219
EDIT: Here is an image from a character that has killed Argus.
https://i.imgur.com/eQi4d0w.jpg
EDIT 2: Omg I feel so silly, some how in all my years of playing I have never seen it but after FuxieDK pointed it out and looking it up I feel rather stupid now. How on earth have I managed to never see this all these years! Its a freaking moon! I guess it just shocked me because I was expecting argus up there while I was on my alt. Sorry to waste everyone time.