This is a follow-up to banning puberty blockers for children under 16 in 2023, pausing or cancelling all trials recently, and the banning of trans people from gendered bathrooms this year.
It's a progressive attack on trans rights, where evidence of the safety and benefits of trans healthcare is ignored and decisions is taken out of the hands of trans people, trans children and their parents. They're treated as people unable to make decisions for themselves. A tactic often used against women, disabled people and black people historically.
In this particular case, it's still breaking news but I've heard the way they fit the data to their desired result was to make the filters on what was to be accepted as evidence extremely narrow. Things like "all subjects in the study must have never taken puberty blockers, but must be on hormones and born male". When they find that no study exactly matches their criteria, they throw up their hands and say "we just don't know if it's safe" and ban all healthcare.
It doesn't matter how many experts criticise these choices and peer-review the reports. We've been shown by the Cass Review (still referenced in these decisions, despite its provably terrible quality) that all evidence outside the transphobic agenda will be ignored and every possible side-effect of treatment will be used as justification to eradicate trans people.