I have a friend who breastfed her adoptive child. Some women can do it by slowing the child to latch and suckle it can be enough to stimulate milk production and then there are the stories of men doing that - mind over matter
So? There are times ie certain cancers where hormone therapy is used https://www.cancer.gov/types/prostate/prostate-hormone-therapy-fact-sheet Do you have an objection to that?
Just imagine if it became a mark of shame if a father was unable to lactate and feed their own newborn sons?