The standard model predicted it and it was found. That's a major win for the standard model, which is the result of many years of theoretical work, as said above - it was able to predict something completely new, something that was never observed before. I'm not deep enough in the field to see what questions could be answered, and we will see, but it's always a good thing to be able to rely on your model of the world.

So - this is not about other questions in the first place, it's about the validity of the standard model. We can continue from there. (A common title for talks etc is "Physics beyond the Standard Model".)