We do not call women in the past cis-women because that would be anachronistic. So why should we call them that now?
Our reproductive systems- whether they work or not - have not changed. So there is no biological difference between women now and in the past. You can argue that better nutrition and health has led to some changes (earlier menarche, fewer cases of contracted pelvis) but the basic reproductive system remains for female humans, as the system which has eggs, ovaries, uteri and XX chromosomes - however well these things work or not. So nothing about biological women has changed.
So we are left with the things adult human females are allowed to do, the ways they can dress, the options open to them - in other words, gender characteristics. Gender based ideas are still based on some understanding of sexed reproductive biology.
Moving away from dress and make up to reproduction, gendered ideas of women’s place in the home were based on has babies = caring and nurturing = female, for example. However, we recognise that men can be caring and nurturing, even if it is seen as a feminine gender trait. So understanding that men can care for babies too is progressive.
Staying with this example, we do not need to argue that the nurturing man is then a woman. It is sufficient to acknowledge the progression in gender roles that child-rearing is not solely based on the sex of the parent. That is progressive.
For a long time, men with babies had a problem because change tables were in the ladies. So we now have change tables in the men’s or separate baby rooms.
Now I get confused. If the same man was told that he was a woman because he was looking after a baby, that would be regressive. Very few men with babies tried to argue their way into the ladies to use the change tables; society rightly recognised the need for a different solution.
But if this man self-ID’d as a woman, because he is doing something long associated with the feminine, we are going to hail it as progressive? Nothing else changes apart from him adhering to a social gender-based role as a main carer. And he wishes to identify as a woman as a result. He says he is a woman, and his wife is a cis-woman (although maybe she should be a trans man because she is the main breadwinner, and that is a stereotypically masculine role).
I mean, it is nonsense, isn’t it? It is perfectly possible to seek solutions which don’t impinge on female space or erase women. Men looking after babies (historically female) challenged this stereotype without suggesting women could not do it and should not have Mother & Baby magazine anymore, and should give up their change tables or let men to use them and so on. And yet men looking after babies (SAHDs) must be as much of the population as trans people.
I don’t know if the analogy works, but it is helpful maybe to look at other instances where gender-based social change has been affected without impinging on same-sex space.