For the greece flights the two main companies are Kosmar and Olympic, both have operated for many years, and prior to SCY arriving with a based aircraft most were operated in reverse by foreign carriers remember TransAer, Cronus etc? So even if XL do not cover these flights, which seems unlikely as HH6072 said XL now own Kosmar, I can't see them not happening. Greece is a big market for NCL and I believe it is (or was) the 3rd biggest source of UK tourist to Greece.
Another round of FJE bashing by the BBC tonight I see, apparently they have sub-chartered an aircraft to operate today's delayed departure and tomorrows while FJEA is repaired, anyone know who is covering?