Very strange.
On the surface maybe, but it actually makes sense.
He has worked with and knows Ralf Rangnick already, and as much as people (me being one) hate the whole Red Bull thing in football, they do run their clubs very well. He'll get a group of excellent young talent to work with, suited to the syle of football he wants to play, they'll spend money on transfers. They are a well run machine. And makes sense career wise for him.