> they're trying to destroy any notion of gender
That would be nice, but you have it backwards. In most cases the an attempt to make gender more central and essential, rather than less, by decoupling it from biology.
Which is why in some parts of the country children are sometimes being told that if they like boy sterotyped activities like tree climbing or boy stereotyped attire that you are a boy, rather than saying any activity or attire is available to anyone.
Rather than erasing gender it's power as a tool for enforced conformity is amplified by eliminating any requirement for agreement with a person's biological properties.
To exaggerate in order to make the point, it's as if we've gone from: "It's a womans' job to do the dishes" to "Anyone can do the dishes." to "The person doing the dishes is a woman, by definition."-- and the middle state's inclusiveness is increasingly seen as hateful because it denies people the ability to identify as a gender other than the one suggested by their biology through the performance of stereotyped behavior.
Erasure of "mothers" seems contrary to the trend at first blush, but it's made more clear when you see the suggested replacements like "birthing person" or "breeder"-- in this world view "mother" is a biological function, so it must be decoupled from gender so that the strongest possible gender sterotypes can be imposed on people regardless of their biological abilities.