If a corporation ever admits doing something wrong, it's admissible evidence in a lawsuit against them. That's why corporations never admit any wrongdoing regardless of how obvious it is that they did.
(And before anyone post the usual "corporations suck" rant, the exact same principle applies to individuals. Anybody who ever watched James Duane's "Never talk to the police" video knows why. Why would it be any different for a corporation?)
That is an odd statement. Corporations admit wrongdoing or mistakes all the time and not to mention there could never be any lawsuit from something like this.
It is just that they introduced a rule and still feel it is a correct one.
Them introducing (in the future) a rule (which we don't know the details of as of yet) is more or less orthogonal to claiming that Monica violated the current CoC.
I don't know if the SO mod (Cellio) is in the wrong, but they did not give any explanation why Cellio was removed. I am unconvinced by this update.