Does AC actually inform their crews of new rules at all? Or do FAs just choose to read what they want to read?

May 28, 2014 AC001 New rule on the first day was recognized by crew.
June 4, 2014 AC856 New rule was not recognized - SD made standard old announcement that all phones and electronic devices were to be switched off for taking, landing, and taxiing. All FAs enforced what the SD said.

Is this discretionary? Did the FAs just crawl out from a rock and went to work?
Why is it so difficult for a new rule to be immediately communicated, understood, and then applied in a uniform fashion?
Do FAs get to make up their own rules?

So typical of AC. So typical.