But it would very logically complete Rumple’s story — he killed his father, it would be logical that his son kills him (or causes his death).
This would actually fulfill the prophecy that never really was fulfilled from season 3a. A boy would be Rumple’s undoing. Here we thought it would be Henry but maybe it’s his own son. I’m one of the people who still believe the prophecy has not come to fruition yet so this would make a lot of sense to me.