It was a pretty rapid improvised panic if that's the case, the music started playing about 5 seconds after the whistle with only a handful of fans only just entering the pitch.
They're just having fun, they sung it in a bar in Manchester a while back and SB started a celebration of it vs QPR at home I think.
We sing about our heroes (them), they just sing anything that is fun and trending.
Made perfect sense to me, withdean aside, on the pitch at the Goldstone with tears in my eyes, 20 years later on the pitch at the Amex with tears in my eyes for different reasons.