Normal
Free Upgrades happen when/if something unusual occurs with the bookings prior to sailing. Sometimes if you book a guarantee say Lowest outside cabin, the cruiseline will upgrade you as they see how booking go as the sailing date approaches.. This enables them to sell your orginal cabin at a lower common price or whatever they can get. All sorts of reasons really. Some unknown I sure. I have yet to sail on a Celebrity ship that does not have a sign the first day that says the ship is full. But I know that that is not usually true so indeed you can get upgraded BUT...they charge you for it.
