*** There’s no particular reason to believe they are Muslim refugees ***
Except for the news reports out of Australia.. The 870 male only camp in Papua New Guinea, and the other camp 9n Nauru hold mainly Muslims. A list of the countries they hail from are Muslim countries.
The camps contain a significant number of Christians as well. Yes, more Muslims than Christians, but still a significant number of Christians as well as small numbers from other faiths as well, and some with no faiths.
Not all on the islands are eligible to be sent to the US. Those who are being presented for that possibility are being specifically selected.
This idea that the camps are full of Muslims is one that is promoted by certain groups that want to claim Australia's refugee policies discriminate against Muslims. They do not - some people would say they should. But they don't.
A list of the countries they hail from are Muslim countries.
Which doesn't necessarily make them Muslims. In fact, Christians from Muslim countries often have specific reason to become refugees because it isn't uncommon for them to face discrimination of various sorts in those countries because of their Christianity.