What facts are you basing your assumption that NCL must be one of EZY most seasonal basis, again I would ask you to look at the STN loads for last Winter. The loads were very good and yet EZY have slashed the rotations on this route for this winter.
This will be mainly due to the increased taxes at the airport. FR have announced that they will be serverely cutting services aswell. The loads may be good, but not good enough with the new charges. More money to be made elsewhere.