I don't think Aubamayang really suited the way Arteta wanted to play. He isn't really a centre forward but was never going to be suited to the left side role he favours. Players like him and Ozil are not really suited to the high press Arteta wants, particularly at their respective ages.
No doubt Arteta was making a point in the way he dealt with him but part of me thinks he wasn't too worried about moving him on.