SW
Unless you know otherwise, I'm pretty sure the BBC do not issue contracts that demand programmes to be televised on certain dates regardless of any events. More than likely he's contracted to do X number of shows a year and the Beeb can show those whenever they see fit.
The Graham Norton Show would have aired - it is his contract with the BBC, they would not have delayed his show I presume.
Unless you know otherwise, I'm pretty sure the BBC do not issue contracts that demand programmes to be televised on certain dates regardless of any events. More than likely he's contracted to do X number of shows a year and the Beeb can show those whenever they see fit.