I was just reading the Compass for the Liberty on Cruise Dailies and it had this mandatory drill at 10 a.m on the day AFTER leaving port. Is this true? The last I heard, I thought it was a Coast Guard requirement that it be done before leaving port. Has something changed in this area?

The Coast Guard requirement is within 24 hours of leaving port. I assume you are looking at the posted Capers for the western Caribbean cruise in June. For some reason they didn't do the drill on embarkation day - and I think it had to do with the norovirus breakout they had on the cruise immediately prior to the one posted on cruisedailies - which had the ship leaving Miami late. So they rescheduled the drill for the first day at sea.

Normally the drill would have been done around 4pm on embarkation day but circumstances got in the way.