I asked Meridian for his new stun meter to be configurable to show this, but only for your units, naturally. Leaving critically wounded gals unconscious, in heavy smoke, for 30 turns sometimes, was stupid - you don't treat wounded like this. Hence this new rule. Minor additional reason - to drowning in an underwater mission, or suffocating in a space mission, be possible.
Enemies and civvies are subjected to this rule as well because I see no reason why should they be exempt. As minor graces, it makes the 'perfect stun mission' much harder to pull off, and puts some cushion-soft constraints on stunning civvies.
I'll refrain from judging which weapon got buffed and which nerfed by this; if lethal weapons which were used for stunning are less useful to that end, then good; if Cattle Prod and Stun Baton got some extra attractiveness, that's good too. About the Scroll, well, at that level, you will have the means to completely subdue most low- to average- threat enemy deployments within 4-6 turns so it hardly matters if they start taking 1HP damage per turn - since Scroll doesn't damage health.