eastern wiseguy It was introduced to prevent pilfering. I expect that numerous other carriers will follow and that all manufacturers will be reviewing this option. It makes a lot of sense.
A couple of years ago, when on board said carrier, I pointed out to the CC that there was no life jacket under my seat (my travelling companion's was present) she just shrugged her shoulders and walked away. Fortunately, there was a spare seat next to me and I had already checked it for a jacket. Had the seat have been occupied, I would have been forced to stand up and break the cabin security to obtain a spare. Such is travel these days.