Here could be a remapping of the area that might make sense:
From:
https://www.quora.com/What-will-happen-to-Syria-and-Iraq-once-ISIS-has-been-defeated
View attachment 4762
However, there are a few problems, like water rights for Shiitestan, as the major rivers would come thru Sunnistan. That might be able to be hammered out via a UN sponsored agreement, but then w/o stable governments, who could claim that it would hold. And the Sunni's would probably be pissy that they have very little of all that oil. I would think the Kurds would like their new official country, and would have enough oil to help. However, the Turks might get rather pissy about it as they would have a much harder time doing what they want to Kurdish "terrorists". And of course the Shiite powers that be in the rump still running the official state of Iraq would most likely not like having their official state ripped apart. And the slashed Alawite state players probably wouldn't be very happen with the idea. And what would be in it for the Russians, Iran, or SA as all of them seem to be playing for a total win? And the west seems to have a real tough time with the idea of redrawing map lines...