What a time we live in.
That is a statement of fact that has been appliquéd to swimmers.
That some people consider it an opinion is their own philosophical belief. That statement of material reality has been deemed to be entirely subjective based on that belief of a philosophical theory that has no basis in material reality. It is entirely conceptual and defies material reality.
Those holding that philosophical belief also have attached a value judgement to that belief and therefore those three words, which as a statement convey no judgement, have been given such incredible emotional judgemental power that it is considered hate speech by some people.
Those who hold that belief (one that defies material reality), wish to ban that statement of fact because somehow society in the UK and other democracies, that not supposed to be authoritarian about beliefs, has come to the point that philosophical belief should given priority over statements of fact.
There really is a warping of concepts at play here. Words have been robbed of meaning by being attributed meanings that are the opposite to the established and intended meaning.
Some people believe this is progress but this change by a small group of society has been given great power. The words are not just those biological terms. But also ‘kind’ and ‘hate’ in the exchange the OP has posted. There are numerous others which will no doubt be used by posters who will agree with the opinions of those seeking to ban statements such as this.
It is the opposite of ‘kind’ to have changed the meaning of words in this way and to then enforce compliance to a group’s philosophical belief.