That is my understanding, I'm ready to be corrected.I did say it was not a good position to be in and most Captains are not happy with commiting to one runway. I am based in LHR so when commiting is discussed "we have 2 runways to use" is phrase used every time.
I have only commited for real once. On a gin clear day so flight planned fuel had been taken. If there is a hint of bad weather (or any other excuse)everyone takes a load of extra fuel. I wouldn't mind betting more palpatations due fuel happen on fair weather days than on bad wx days.