Does your son realize that his baptism is viewed as a "legal contract " by the bOrg? (If he should ever try to escape it or annul it).
Does he remember that Jesus, of whom JWs are supposed to be footstep followers, was baptized at the age of 30????
Does he appreciate that the WTS frowns on people marrying too young, fearing they may not be mature enough to enter into a lifelong relationship, which is to be taken very seriously??
How then, can a child or youth make such a decision to be bonded to Jehovah "AND HIS ORGANIZATION" ( note that they are viewed as almost one and the same) if he isn't even mature enough in the Society's eyes to make a commitment to marriage????
And never mind the example of young Samuel, as the JWs may try to argue -- it does not negate the above points.
Also, do you not have any say in this matter as the child's father? Insist that your son wait until he is at least legal age before making such a decision as to baptism. If his commitment is genuine, it will stand the test of time.... (And the threat of disfellowshipment cannot be weaponized against him before that time! Your son need not be subjected to a "captive organization" while still a minor!)