Despite having the same parent company, if an airline goes bust, wouldn't the airport operator put the slots back up for sale/auction/whatever? Can another airline just take them straightaway? Surely if there is some value to the slots then they should be paying the administrator for them to give back towards the creditors?
Only if demand for slots massively outweighs supply such as in the case of Heathrow. If there's plenty of capacity, where's the monetary value in a slot?