It is an erasure. Any woman whose gender identity is embodied, i.e., who is a woman because she lives with a female body has her gender identity erased (to use the trans-cult language). She can no longer be a woman on an embodied basis but is told that she possesses an abstract identity which just happens to coincide with the sex of her body, and that other people have the same body but do not identify as women so 'pregnant people' is required to replace 'pregnant women.' To be inclusive.

But that inclusiveness denies many, many women the basis on which they accept the label 'women.'

A corollary is that there is now no non-pejorative name for those who are of the female biological sex. Yet that is the very group which is suffering from sex-based forms of oppression.

Another way to think about this is to ask what would happen if, say, communists were called just 'people' because they clearly are people. Doing that erases the focus of what they identify with (in trans-cult language).