Thanks to everyone who replied. Here is the precise language regarding the concierge service directly from the NCL website.
With one quick phone call or email, you can arrange for a variety of special requests which will be handled before you even arrive on board the ship! Would you like a special pillow, or perhaps you’re a fan of chamomile tea? No problem. Maybe you only drink milk with your coffee? If so, they’ll have a pitcher of milk waiting in your mini-fridge. Perhaps you’d like to start off your first sea day with a massage and facial at the cruise spa… they’ll arrange that, or specialty dining reservations, shore excursions, and more!
When I read the paragraph above it certainly seemed to me that the concierge would be able to arrange shore excursions (they can't or won't). Along those lines, it didn't seem unreasonable to expect that "and more" to possibly include arranging a private airport transfer, again the concierge can't or won't help with that either. A certain type of pillow or a cup of tea can be arranged very close to a cruise departure, however, waiting until we are on board to book a shore excursion during the peak summer season seems like a bad plan. Alas, it seems that we are on our own with regard to advance planning.