Wow, sounds ludicrous. I cannot believe they have spent time and energy on this plan which will pee their passengers off big time. If you are rushing and stressed, the last thing you need is someone saying "your plane won't be leaving for 30 minutes, but we're not letting you try to get to the gate".
“Gatwick security control gates are automatically being timed to close 30 minutes before departure.”
And what if the departure is delayed? The departure could be delayed at the last minute too, which would mean refusing passengers who easily could have made it.
Stupid stupid plan.
Easyjet: Always getting worse.