However, this is Supernatural and there is bound to be a fair amount of conflict between Sam and Dean in season 13.
Dabb is certainly correct in his belief that Sam and Dean taking care of Jack could bring out different sides to the two protagonists.
Sam and Dean Winchester will be thrown straight into the deep end of parenting in Supernatural season 13, as they raise the child of the actual, real-life devil Lucifer himself.
Furthermore, Jack is the unique position of being an immensely powerful adult but with no experience of life on Earth.