depends on audience reactions, they can develop Superkid if the general public accepts Jason warmly, if there is massive resistance WB might insist to scale the kid back.
frankly i wont be surprised to see Superkid in either the 2nd or the 3rd movie. Singer is moving the franchise forward and if WB likes the direction its going to-- and that its making money, then you can expect Jason to be firmly on his way to be Superkid sidekick.
i dont like it myself.
but that's the reality of life.