Would have been at Stansted about 2255z. We are doing some reduced distance runway work at night and after the last dep goes we wait 5 mins and shut. Obviously what with aircrew being generally tight lipped about any kind of problem we like to make doubly sure you don't plan on coming back in a hurry as the runway is closed for up to 15 mins to prepare for reduced distance ops. If you think this is a bad idea then I will ask ops to review the procedure, it does seem slightly pointless and when I asked it the other night it occurred to me that the crew may think I had seen something untoward...