There is an agreement in place.....it's been acknowledged by Easy management. That is why LPL and MAN have been having aicraft added simultaneously and is basically why DSA has Easyjet flights today.
Loads out of LPL are indeed good but that doesn't mean that MAD from both LPL and MAN is sustainable, not least by the same airline.
Those who moan about EZY's choice of routes should be comforted by the fact that MAN has been the pioneer of long distance flights that are gradually being seen right across the network together with relatively new Easy destinations such as HEL and (if true) GOT.