All I can do is echo some of the responses by others who have articulated this well:
All students deserve a safe learning environment. This includes those who are LGBTQ+. As someone who has friends in the LGBTQ+ community, I can say with confidence that bullying, harassment, and institutional and individual discrimination are extremely damaging to children - to their learning, their mental health, their physical wellbeing, their safety, and their lives. Transgender children deserve to be respected for their own identities, just as cis-gender children are. This policy is way overdue.
In response to community members who have claimed that LGBTQ-supportive policy will "damage" their own children, I encourage them to really consider what that damage would be. Having views that differ from those of their parents is not damage. Treating their peers with kindness and understanding is not damage. Accepting others whose identities and ideologies differ from their own is not damage. But discriminating against LGBTQ+ individuals is unquestionably damaging.
I support this policy with full conviction and enthusiasm.