Good to see you again, Emma, you should come here more often, we need more BVB fans!
Personally I'd like to see him coming back to BVB despite the fact that his departure, and more importantly the manner in which it was announced and conducted, pissed me off so much. I still think he can add a lot of value to the current lineup.
That said, I don't think it is practical given he is paid handsomely by the mighty Bayern and he won't likely accept a paycut to come back. Also fan resistance could be an issue.
Speaking of Aubameyang, he did hint several times that one day he would go play in Spain as a promise he made to his grandfather. If he pushes to leave, BVB will have to sell him, even without a release clause.