I think there is an issue with the fact that sitreps in the Core book are extremely specific: they suggest cover placement, enemy force size, deployment zones, reinforcements zones, and most importantly, codify a win condition. More experienced GMs shouldn't have much trouble coming up with a win condition for De-escalate and making a map that's suitable, but if you want this to ease new GMs in as well as new players you should take that burden off of them.