If Aubameyang isn't a crucial player for Chelsea, Chelsea management won't force them to sign Aubameyang on the last day of the transfer window. If you followed the issue on Chelsea squad, you must know that Chelsea was looking for a strong CF to be the replacement for Lukaku. Chelsea needs a pure CF to score more goals, Aubameyang is a perfect player to solve the crisis in Chelsea attacking line. Anyway, Havertz isn't a pure CF, so he has nothing to do with Aubameyang's position. Don't you understand that Havertz is an attacking midfielder? 
Honestly, I think Aubameyang is a good player on the pitch. Maybe off pitch he has had some issues. I am quite sure he will deliver for Chelsea on the pitch. He is the kind of guy who can fit anywhere, but sort of unlucky not to settle. Look at what happened in Barca last season. He literally saved them from the embarrassment, only for them to push him out.Aubameyang is a football player who is very successful in his own region on the field. We have to accept this. He went to Barcelona last year and took Barça off the rope in many matches. Frankly, I thought that he would not be successful when he went to Barça, but he made a show in Barça. I am confident that he will be successful at Chelsea as well.