As others have pointed out, it's not been banned, it's just that choirs will no longer be singing it.
There's nothing stopping fans belting out the chorus of Delilah.

I don't see the relevance of pointing out that lots of traditional folk songs have murders in them, that's a totally different thing. They're not being sung as feelgood anthems by choirs at Welsh rugby fixtures.

I'd wonder what was going on their heads if football crowds started joyously belting out 'Child Owlet' or 'Pretty Polly'