Transfers from the hotel to the pier are commonly included when booking your hotel through any cruise line, but they are not "free". The per person hotel rate they offer includes the transfers, and often the taxes too. It will not be as low a hotel rate as booking the hotel on your own would be, but is often worth it for the convenience of the transfer.
Sort of like "free dining" at Disney, not actually free if you have to give up a promotional room rate and book a rack rate room to get it, but still worth it for lots of people.