I have to politely disagree with the comments about the drills needing to return to the days of all the passengers packed together wearing life jackets. There is no evidence that method was better, in fact there is much documentation that putting people in a stressed situation (such as wearing life jackets and being sardined together on an open deck) reduces their attention span and therefore is adverse to providing training or instruction. I know what I am talking about. I provide training in industrial safety and radiation protection as a profession. The 'old' way has the appearance of being better, but that is all.
By and large, most passengers will be more attentive to the drill if they are not encumbered. Remember that these are passengers and not employees. The cruise lines have no realistic expectation that the passengers either listened or retained any knowledge. All they can do is comply with the law and trust that their crew will handle a situation if it arises.
That said, there is room for improvements in crew training and the stricter enforcement of conducting the passenger drills for ALL newly embarked passengers prior to leaving port. And it is apparent communication breakdown was a key element in this evacuation.
Regarding the Oasis/Allure...the rescue vessels (life boats) are positioned such that passengers directly board them from the deck with no need for repositioning them prior to lowering to the water. This is a superior design.