They may not change the storyline of what they originally shot, (though they’ll re-shoot it with new actors anyway), but Rumple’s father was previously in 1 scene, and will now be in 2 eps, which means they’re expanding Rumple’s backstory and will be showing a decent chunk of his family life when he was a child, which means there’s more significance to that family life than just showing how his father died. If anything, I’d say that the expansion of the father’s role suggests that there may be some merit to the brothers theory.