If the regs state that the jacket must be worn, and the EAM product comes with a strap to strap it around your waist - aren't you then wearing it (for the purpose of the regs) even thought the jacket itself is still within its protective package?
As you don't inflate life jackets inside the aircraft anyway, I would have thought that the purpose for the regulation is that you have a jacket on you if you have to jump into the water with little or no notice. haveing the thing strapped to you waist would seem to meet that requirement.