EZY7452 ARRECIFE 2250 OPERATING TO STANSTED
Arrival 22:50 Estimated Sat 14th Jan 03:27 Stansted.
As a result of this diversion your crew will not have enough working hours to operate your flight to Southend. Therefore your flight will be landing into London Stansted.
Didn't know the flight time to Southend was so much longer than to Stansted.
More likely that either Southend's terminal did not want to stay open all night together with the fire cover or easyjet was not willing to pay the airports overtime bill.