Of course this event has the usual over-hyping marketing gimmicks that we are used to from Princess (but, to be fair, they are not alone in employing over-hyped marketing to try and create excitement).
That said, it seems clear they need to tweak this to allow similar benefits to folks who want to travel down to FLL the day before. No way, I would take a same-day train.
As for Port Canaveral, I like driving anyway, so I wouldn't want to train it to MCO and then have to shuttle to the port. I'd just drive there.
AFAIK, there is no sort of commuter service between Naples and Fort Lauderdale. Sure, a bus service, but nothing special there. The old rail line that ran from Naples up the west coast through Fort Myers is going to be turned into a cycling/walking trail in coming years. From the southwest side, driving is the best option IMO.