There are still many issues that will not be addrssed by the terrorist groups defeat
1) Having control over much territory now, the Kurds are very unlikely to reliquish it to Iraq or Syrian. They are effectively already their own state, but its equally unlikely that Iraq or Syria will accept this Turkey certainly won't.
2) Speaking of Turkey, correct me if Im wrong but the dark green patch in the OP map in the top left betwene the 2 kurdish areas, that is occupied by Turkey. Syria and Turkey could quite easily come to blows over that is Turkey are reluctant to leave.
3) Despite the call to return, most refugees won't. That will leave Syria in particular whivh a hugely war-ravaged infrastructure with a vastly reduced population to try and aid the recovery. There won't be much progress anytime soon.
3) The terrorist group may be defeated by other rebels are still active and dug into. These included the free syria alliance as well as other islamic terrorist groups. The war will continue.