I was also wondering about this. As far as I know it has never been against the rules to call any off-board person a cunt in any forum.
Here is Ed Zotti making that clear shortly after the prohibition on calling other posters cunts.
And here’s just one example from Cafe Society specifically in which at least one mod even participated in the thread:
Eat Pray Love (the movie): is Elizabeth Gilbert a cunt or is it just me?