Its a baby ? It doesn't know and many babies are separated at birth for lots of reasons
Human babies don't know much when they leave the womb, hence the 4th trimester, but one thing every baby does know is his or her mother. They know her voice, smell and they recognise her face before anyone else's when they being too see shapes.
Babies who are separated from their mothers at birth can and do suffer attachment and development disorders. It can range from eye contact to speech. This is not new information.
What you're saying here is babies don't know so it doesn't matter, but neither are true.
Ever known a baby not settle with anyone, even the father and only with the mother? Ever heard about babies being unsettled at night if they haven't had time with their mother in the day but have been passed around to relatives? Ever heard about surrogate-born and fostered newborns babies being colicky and crying themselves into an exhausted sleep.
A friend of mine had to have emergency surgery when her newborn was less than a day old. They were separated for about 6 hours. She struggled with her milk supply but persevered. Thankfully all was well but it was a rough beginning for mother and child, and too for the husband who thought he was about to be a widower with a newborn. The baby would only settle with her mother for months and she largely attributed it to the early separation.
Many adopted, fostered, orphaned and surrogate born babies grow into well-rounded adults, it doesn't mean there aren't mediate impacts on them as newborns or infants.
We simply don't know enough, but as some surrogate-born adults are speaking out we can take their testimony as truth, and that the circumstances of their birth matters to them.
Jessica Kern
vimeo.com/125756487
Various speeches from donor conceived adults and others
https://youtube.com/channel/UChwdgQDLzLBfFxLLfobyoyw