I just checked NCL's Web site, and they have not announced any itinerary changes.
It's been my experience that you might not find out until boarding. In 2005, we were booked, ironically, on Norwegian Majesty to Bermuda, only from Boston. A category 1 hurricane was to the west of Bermuda, and we didn't know if we would be heading to Bermuda or north to Canada. I remember calling one of my friends from an onboard bar just before we left to let him know we were, indeed, going to Bermuda. To tell the truth, we were all surprised -- even my buddy on land. It turned out to not be so bad.
I don't know where you'd go from Philly if Bermuda is not an option.