The story is Dortmund need a replacement before approving the deal, they wanted Giroud he's said no and is apparently off to Chelsea with Batshuayi going to Dortmund.
All change at Arsenal this window they've ended up with 2/3 of the great Dortmund front line from 2 seasons ago.
Aubameyang would not be able to play in Europa League because Dortmund have dropped into Europa League competition meaning they have to use their 1 extra squad place for Mkhitaryan.