As per Andrew Tse comment, thought had been given in the past to carrying liferaft on these flights, but they chose not to. Payloads would have been reduced in summer if carrying LR on S76C+, but not sure if the same economic argument can be made with AW139. There is no mandatory requirement under many jurisdictions to carry liferafts in a Class 1 performance helicopter operating over water <100nm from land, or even the wearing of lifejackets for that matter. Some passengers had trouble even finding their lifejackets let alone putting them on, the prospect of them being able to assist the crew in launching a liferaft is remote. Unless of course an automatically deployable liferaft system was installed.
I would be surprised if they changed what they've being doing up to this point, i.e. stowed lifejackets under seats and no liferaft. A better "wearable" (but stowed) type lifejacket might be a more practical option, as opposed to one in a pouch. There is so much marine traffic on that route that sea rescue would never be far away, and all of those fast ferries have thermal imaging cameras that should assist in detecting survivors in the water.
No doubt they will take a look at all these aspects again in light of what happened.
I'd be interested whether the SkyShuttle pilots practice loss of tail rotor components in the sim, or just loss of tail rotor thrust, and whether the sim experience of this was similar to what the pilot found during the event.