It could be the worst move for Aubameyang really. He shouldn't have come to Chelsea in the first place. Now he is even out of the Champions League squad. How can he motivate himself to play better now?
Besides I can't say that his performance at Chelsea has been more impressive than the one at Barcelona. He should have wanted to stay at Barcelona and wait for only Depay to leave instead. He could have still been a useful substitute for Lewandowski. His performance was already great there. Maybe he wanted to play more by coming to Chelsea but here we are. He isn't a very important player for the team currently seemingly.
One of the reasons why Aubameyang leaving Barcelona was because he wants to get more opportunities to play. Having Lewandowski makes Barcelona to send Aubameyang on the bench, so it was no chance for Aubameyang to play regularly and be the main striker. Sadly, he also sits on the bench when he comes to Chelsea. I don't know why Chelsea coach not select him as the main striker in every match. I think Aubameyang has everything to be Chelsea main striker. He is fast, accurate in shooting, and has the ability to deliver assists very well. Actually, he is an ideal striker for Chelsea, right?
The difference between coaches is clear. We know that Auba wanted to go to Chelsea, in addition to adding playing time there, there was also Tuchel at that time, who he was really interested in, but after he was at Chelsea, his condition did not go as it should, especially after Tuchel had to be forced to leave.
There have been a few young players brought in in the Potter era and with this things are getting worse and I think if he does get some game time eventually he will leave again sooner or later.