As always, people get very aeriated ( in both directions) without reading the source material.
As has been said, no-one is banning the word mother, and patients in maternity units, as in all hospital units, or collecting children from school or comforting them when they are hurt or unhappy, can choose what they prefer to be called and referred to as. (Grammatists may say I shouldn't end a sentence with a preposition, and that one has TWO. I don't care. It makes sense.) The document is a policy one, setting out aims for those drafting official docs and legislation, so as to include those who don't wish to be called (or referred to as) mothers. All very laudable and inclusive.
What most of those on the deleted thread would asking was why not ADD the preferred category names for those non-mothers instead of REMOVING the traditional and universally understood name for the person who conceived, gestated and gave birth to a child (which only a natal female parent can do and natal male parent cannot) and REPLACING it with another term which is so general it may as well just be "person".
It got inflamed because a couple of posters argued the cause of non-mothers very enthusiastically, and considered those who disagreed with them as bigoted trans-haters.