"People that don't exist can't present any threat to women's rights surely?"
Correctly categorising this group of male people doesn't 'deny their existence'. And your repeated point simply doesn't make sense.
A group of male people are again causing significant pressure on the rights for female people to have single sex provisions. What is different compared to any other group of male people trying to remove the rights of female people to suit their own political agenda and their own wish list?
You are telling us there is a difference between this group of male people and the other groups of male people. They are all part of the same patriarchical structure, just because we reject their demand to use the category label doesn't make them disappear at all.
FFS. This is basic material reality. If we removed the label for female people altogether, will that mean that female people cease to exist in reality and that some how those female people don't still have the same needs as when we used the terms?
However, forcing the collective category label to include a group of male people (who are part of group oppressing the collective of people known as female people) does indeed significantly decrease the protection of that collective group. The group of female people still exist, but there is then no way to protect their needs.
So, the male group of people exist because they are still part of the collective category called male people and they certainly do continue to threaten 'women's rights'. I am not sure how you are coming to the this soundbite of 'if they don't exist they cannot present a threat to women's rights'? It sounds more like a superficial soundbite than a thought out rational response.