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.when off the field it has become a personal matter and what is important is the game on the field that can make Chelsea win the Premier League this season. Aubameyang is a very talented player and scores goals. Half a year at Barcelona in the Spanish league and before that Aubameyang was also still in Arsenal's uniform. This is a reunion for Aubameyang to be able to appear again in the English Premier League but with a different club, Aubameyang uses the number 9 shirt at Chelsea. At arsenal, Aubameyang was captain and was able to score 29 goals from 163 appearances and this time when he was in Chelsea uniform could he score more goals, of course this is a new challenge for him.