I think you can fairly reliably tell the quality of news source based on what they call this organization.
You should just ignore anyone calling them ISIS. At least listen to anyone who calls them ISIL. Anyone who still calls them IS, or the Islamic State, needs to get with the times. Finally, you can probably trust that anyone referring to them as Daesh knows what they are talking about.
https://www.bostonglobe.com/opinion/2014/10/09/words-matter-...