Usually sires don't hold maternal insticts like a bitch would but you never know. There isn't a relationship with canines like there is with humans relationships, seen females kill their own offspring before for no reason.
I don't think they would recognize each other after two months. But I knew a male who helped the dam take care of their puppies. He even cleaned them if she was tired and he always let her eat before he did when she had pups. So I guess some males have a small amount of paternal instincts. This is not the norm for a male dog, much less a pit:however it did happen.
My friend had a pug that would jump in the whelping box with it's half-siblings and care for them when the mother was eating or going potty etc. He would clean the pups, and curl around them to keep them warm, very cute. I think some dogs just like puppies.
I wonder the same thing about litter mates .... sadie and simba they are littermates came from the same parents .. And they seem to have an extremely close bond since they were never separated at birth and have grown up together .... I wonder if they remember each other as being from the same litter .... If they feel any special bond with one another because they came from the same litter... Prob not but it def makes you wonder