I dunno. Why is that necessary?
I'm sure they'll do it at the opening ceremony, but for the most part this is a new millennium, a new age (of globalisation, democracy, and the Internet/electronics), and everybody is already fairly well aware of Britain's traditions and culture - I mean heck, they created like half the world's democracies.
And maybe they are expressing their traditions - freedom and multiculturalism. I mean, their performance was in stark contrast to the rigidity, conformity, and sickening perfection of China.