I’m 60% sure that was supposed to show that Anduin was acting unreasonably because he was being influenced slightly by N’zoth…
But, considering Blizz’s hints are usually delivered via sledgehammers of “LOOK HOW SUBTLE AND NUANCED THIS IS” to the face, I’m also thinking that this might have instead been meant to reference and pretend to resolve all the gripes people might have with Wrathion so he can get back on track as the sudden main character of the N’zoth story.