'Trans women are women and trans men are men' sounds a little out of date.
We've noticed over the years that TRA claims and statements have shifted, perhaps in response to public opinion - 'born in the wrong body' was quietly shelved, possibly because it was so obviously clashed with 'body positivity'.
I've noticed recently trans people acknowledging that they haven't actually changed sex - possibly because they have become aware that even people without so much as an O level in biology weren't buying it - they have just changed their gender presentation, and demand to be accepted as such.
[Dr Upton is an obvious exception to this- he claims to have become an actual biological woman]
So it may be perceived as unhelpful that to have non-trans MPs proclaiming the absolutist 'trans women are women and trans men are men' line of yesteryear.
The problem for TRAs of acknowledging that only gender presentation, not biological sex, can be changed is that it sweeps away their claim to be allowed use the single-sex facilities of their choice, as these are designated by biological sex, not gender presentation.