Don't know about the aircraft, but they won't need them if their online and telephone bookings system continue to work as they do at present, including their sister company Freedom Flights. They are working as new business refusal departments.
If you don't want your journey to start in the UK, the online booking system of XL won't allow you to do that. If you telephone XL you are told to ring Freedom Flights ("our sister company") who handle all bookings for flights where the journey does not originate in the UK.
The people at Freedom insist that they can only book such flights where the return ex UK is in multiples of 7 days from your day of departure, as they have to match the inbound and outbound pax. Clearly a load of tosh, when you are not so restricted on shortage or length of stay, when your journey originates from the UK, which can be booked online with XL.