The current isis is now in a state of "hudna" -- strategic retreat and regrouping.
They may eventually reappear in numbers strong enough to go on the offensive again.
But... it doesn't matter whether isis regroups or not.
There will always be a new cadre of islamic jihadis stepping up under one name or another.
Wipe today's jihadis out, and new ones will spring from the ground.
It's what islam... is.