The early months of a kids life are when both parents and child are best primed to bond. Weaning ages for any number of animals is set based on this, or should be, at least, which is the only, limited comparison AOC was making.
No, a mom going to work coz her available maternity leave has ended is not a permanent separation from the baby. But it doesn't have to be to cause the harm it does by reducing time for interaction between mom and child.
That is the choice this country forces on women. Either take time off after maternity leave and lose pay and future career growth to stay with your baby now. Or go to work in 6 weeks and keep a career trajectory that's good for the long term benefit of your child.
This is not a fair choice. It is not a productive choice for an economy to force on its workers. It is not a moral choice for a society to force on its women.
But by all means, let's debate whether women are being forced to sell their kids 8 weeks after delivery. You know, important shit.