No way to predict really. Sometimes they will crank out a set of leaves right after a cone (not a bloom by the way since it's not a flower). Sometimes a cone can sit there for a year or two before new leaves erupt. I have had one erupt new leaves out of the center of a cone, but that doesn't happen too often. Cycads tend to be on their own schedule and do things when they want to. Friend of mine had a mature cycad sit there for nearly 6 years before flushing some leaves. I had a sago transplanted a few years ago and no leaves at all for nearly 2 years. I was wondering if it was dying. Now it looks fine.