I've been playing a Superhuman ironman (no reloads) game. I had my base attacked and after the attack, two of the three Workshops were gone. I know this because I suddenly had no workshop space and many idle engineers. I've played XCOM several times over the years, and this is the first I recall any facility being destroyed by an alien retaliation. Note I mean facility not base. I've definitely lost undefended bases before.
So is this a Superhuman feature or an XComUtil feature?