It may seem like that, but I think the reason he uses ISIL is because that’s what it was called by government agencies when it first popped up. They don’t like to change these things because it messes up the books.
This is kind of like how the government spells Osama Bin Laden as “Usama Bin Ladin” but the press uses Osama.
Also, a lot of the Gitmo detainees transliterate their names differently than the government does.
John Kerry says daesh.
I believe you’re right. I think the original reason the intel community used ISIL is that it is a more accurate translation of the Arabic name of the group, particularly the ‘el-Sham’ at the end.