Clarity: Sexual orientation (LGB) is about who you are attracted to. “T” is about identity. They are different categories and should not be blurred together.
Thank you for making this really important point, SingleSexSpacesInSchools.
LGB and TQ+++ are different groups of people with different identities and different issues, and as you say, should not be lumped together.
Hence the LGB✂T campaign.
Best of luck with your talk OP. Keep it strong and matter-of-fact.
' I tend to be very fact driven' isn't necessarily a bad thing, and needn't come across as confrontational. It's a plus point that you are the one with the facts - and, increasingly, public opinion - on your side. Presenting them calmly and neutrally, as ...well, facts, puts it up to the other side to refute them, or come across as reality-lite.
Try not to get drawn into debates about things, don't react to emotive red rag phrases like 'toxic culture wars' 'transphobia' 'be kind'' 'it's complicated', just keep to the facts.
Keep a cool 'That's as may be BUT this is what the facts are....' attitude, as much as you can.
Good luck!!