Hi Janice, I wouldn't expect or count on an upgrade with a guarantee cabin.
If it doesn't matter where you are on the ship, book a guarantee for the lower price. If you don't want to be in certain areas (like under a dining room or the galley), you'll be better off booking a specific cabin.
You still might get an upgrade offer, but you'll have the choice of accepting or declining.
The upgrade fairy is very fickle
! I'd never depend on her to show up when I need her!