It's an oblique reference to the royal culture of the time, which was indeed pretty cult-like, but also - I believe he is referring to Elizabeth II's coronation

It's an oblique reference to the royal culture of the time, which was indeed pretty cult-like, but also - I believe he is referring to Elizabeth II's coronation as it was a fairly significant socio-political event in the Western world when it happened - the crux of the British Empire, one might say, and by referencing it, Joel made a pretty wry statement about the world powers ..