Ficus have somewhat of a reputation for dropping leaves at times, but as long as you give proper care through that time (usually involving a drastic decrease in the water applied) they do indeed come back well. I've also got a willow leaf that I winter indoors and about 9 months outdoors. It just got done dropping the last of the indoor leaves about a month ago, but started putting on twice as many leaves that were half the size a month before that from all the extra sun and better/fuller watering. Even with good light and attempts at keeping humidity up in the winter, the difference that being outdoors makes always amazes me.
Craig