//without knowing what the slogan actually was//
One such IRA slogan is Tiocfaidh ár lá which apparently translates as "Our day will come". One would not be surprised if this is what the ladies were chanting. Southgate's boys sang (almost in unison)... 'It's coming home...' Both phrases are intended as a 'gee up' and are grammatically in future tense.
Personally I have been more moved by opposing football fans mocking the 1958 Munich air disaster. Namely and fairly recently, a small mindless contingent of the Man City crowd visiting Old Trafford, found themselves being ejected from the ground for such behaviour. It's somewhat strange that in English Law (to the best of my knowledge) one cannot libel the dead, yet one imagines, given the right atmosphere being the recipient of such taunts, proves efficacious in raising a man's blood!
We ought to bear in mind, freedom of speech does not mean freedom from responsibility!