Our bodies react to weight gain by stretching existing skin to cover new fat storage, but because skin can only stretch so far, sometimes they're also forced to create new skin. Skin is a barrier that protects our organs against the outside world and it's the largest organ in our bodies. If we add a lot of fat to our bodies, it HAS to be covered with skin, whether stretched or new. A lot of us get mad at our skin, but really, it's doing the best it can to take care of our bodies.
Anyway, no one can tell ahead of time how their skin will react to weight loss and whether their skin has a lot of elasticity or not. I moisturized a lot with cocoa butter while I was losing weight because I heard it was good for stretch marks. It smelled awesome but didn't do anything to keep me from having excess skin. I think moisturizing is always a good idea, but don't count on it making a difference in how your skin looks after weight loss. There are a lot of other factors like your age, genetics, and amount lost that will make a much bigger difference.
Definitely check out the sticky!