I've not seen anything about this, but have obstetricians and/or midwives (or their colleges) said anything about the idea that they "assign" sex at birth?
Surely anybody who assigned sex to a baby, rather than observing it or, if there was a problem, running some tests first, would be guilty of malpractice? To say that medics aren't following (very) basic science and publicly and repeatedly this over an extended period is surely something there would be professional objections to?
If nothing has been said is it because they're afraid of the trans lobby (which seems insane given that most people are actually in agreement with basic biology), or do they think it's not actually important, because they're not about to change what they do anyway?
Either way, there's no way that it has escaped the attention of all members of colleges. So the silence seems strange.