Pro and con of bringing your life jacket to muster.

Pro- I t gives you a chance to actually try the fool thing on. It is not an easy task putting one on the first time since it is not a normal type of attire. All the straps go somewhere and if you don't do them up correctly, you are going to make things worse rather than better. You also need to know how to maneuver in one. Your vision is restricted and without practice you are going to be clumsy.

Cons- They are awkward. Having everyone trying to negotiate stairs in them is a disaster waiting to happen since they are awkward.
They are unsanitary. Unless the crew were to spend a lot of time going to each room and hitting them with sanitizer after every use, they would be a great vector for infection to spread. When you are on a sinking ship, it is the least of your worries. Just putting them on for a trial run is not healthy. And don't even think about the whistles!
They are uncomfortable. People are less inclined to listen to a lecture when they are uncomfortable. That is just a statement of fact.

It is up to the passengers and the ship to weigh the options. This will determine the course of action in the future.