Why would BA Cityflyer want to fly charters from SOU to the Mediterranean beaches when this a) potentially competes against their own route from Heathrow, b) they have a profitable alternate use at Stansted that involves going to the Med and c) there is talk that LCY might possibly be available for use during its current weekend curfew ?
Not saying it can't happen, but I imagine the charter rate for BA Cityflyer at the weekend would be rather high
Summer charters at SOU in a post-Flybe world could still happen but I think it might need an airline other than BA Cityflyer. Perhaps Air Baltic might be persuaded ?