"The ad doesn't focus on or prioritise trans over biologically female mothers".
But it absolutely certainly does. In the scene where the woman has a transgender partner, the focus is all on the person who provided the sperm in order to create the child. That person talks exclusively about what it is to be a real mom.
The actual biological mother of this child sits there silently - not a word said. Because presumably she doesn't know what it is to be a real mom. Her experience and her thoughts are irrelevant and worthless. Why is she being denied a voice while per partner is given a voice?