First, I am not sure that they are a sign of giftedness except perhaps when it is across the board so that your child truly functions as an older child. As to your question, it makes complete sense to me that mastering some basic motor skills at a younger age does not predict future talent in any particular sport. Just because you can run does not mean you can run really fast. Even in cognitive areas, just because you learn to read earlier than someone else does not mean you will read at a more advanced level than that person five years later.