Aubameyang stay dortmund till 2021
I think there may be some confusion here!
Pierre-Emerick Aubameyang has never played for Borussia Dortmund until 2021. In fact, he played for the club from 2013 to 2018, before joining Arsenal FC in January 2018.
So, it's not possible for him to have stayed at Dortmund till 2021, as he had already left the club by then.