It has been known for a while that Backbone will operate the rest of Powdairs flights but this announcement refers to the internal flights by the leased Adria Switzerland Saab, last week Powdair announced that they had cancelled intentions of flying from Sion to Zurich and the deal with Adria Switzerland was off.
I don't think Adria Switzerland will exist as an entity once the Ethihad investment stopped!
Incidentally Powdair have recently bought 25% of Backbone Aviation A/S registered in Denmark.
Powdair are still using the CR200 but as far as LCY is concerned I don't know what aircraft they intend to use.