There's generally substantial enough reductions in August
Bordeaux, Girona and Reus cease
Stansted goes from 3x a day to 2x a day on some days
Malaga goes from 4x weekly to 2x weekly
Faro goes from 4x weekly to 3x weekly
Wroclaw goes from 3x weekly to 2x weekly
Also Pisa operates with a Pisa-based aircraft rather than a Cork-based one
As Gatwick goes back up to daily in September (and Stansted goes to 3x daily), the best guess would have to be that there's a better yield to be had from keeping one of the sun routes operating in that period.
I could see some eye-watering prices to London emerging from this.