I have two mature sago palms (12 to 15 years old). They always have their new leaves emerge about the same time each year. This past spring, one's leaves started coming out and I cut away all the old leaves. Thinking the other one's were coming soon. I went ahead and cut all the leaves off that one. Well it's been months now and it hasn't produced any leaves. What can I do? Did I kill it? The trunk still looks good.
Generally, sagos don't like hard pruning and may or may not regrow. That being said, they have been known to grow back beautifully. I have seen the sago palms pruned back so hard that there were just a few of the fronds in the center and the rest totally pruned back to the center hub. People thought the sago was a goner, but it grew just fine. With these plants, it's pretty much a wait and see kind of thing.