http://www.huffingtonpost.com/entry/catholic-school-muslims_us_567161d1e4b0648fe3019517
etc. etc. etc.
Their being students at a Catholic school means nothing with respect to their religion.
Locally, that’s not the case. The school does take a very small number of non-Catholics - these students do not seem to have been among that.
There are other places where Catholic schools routinely admit non-Catholics - including some other places in Melbourne. That particular school doesn’t because Catholic have priority entry and there’s a shortage of Catholic school places in the area, so the vast majority of the students are Catholic.
Understand I am a teacher at a Catholic school in the same Archdiocese and am also involved at policy level for the Archdiocese. I know the features of the school, and I’m involved in discussions at Archdiocese level about what went wrong.