easyJet's agreement with MAG
Interestingly, this mega announcement has only come from one side of the deal - MAG. There is no mention of it on the EZY website, just on MAG.
That clearly indicates who was driving the deal, and it isn't EZY. I suspect MAG wanted a 'big' announcement, and EZY took the opportunity of fixing costs in case they have a change of heart over STN some time in the next 5 years.
Perhaps MAG are beginning to realize how seriously they have overpaid for Stansted.