It's doing the leaf-drop expected after the leaching. You should be seeing new leaves popping out in a couple of weeks.
Have you fed it yet? You could use quarter-strength Miracle-Gro now.
Very few pests or diseases attack Ficus, especially indoors. The biggest issues are light and water. Your lighting is great so that leaves watering which you have down pretty good. You can check the moisture near the bottom by sticking a wooden or bamboo stake into one of the drain holes. If it is very wet, wait a little longer to water.
Overall it's doing what is expected and careful, but not extreme, monitoring of condition is all that is needed for now. I normally treat my houseplants like the ones I maintained in offices I card for. I visit once a week, check moisture, groom as needed, check for pests (not usually a big problem indoors) and maybe use some leaf-shine. In between, I enjoy the view and relax.
