The reason you see people concerned about this is because most people assume Trump will defer to his VP on most policy stuff, and his VP is very, very anti-gay. The reason people assume this is that one of the other people considered to be his VP pick, John Kasich, told the press that when Trump's son pitched the job, he said that he could be "the most powerful vice-president in history" and that he would be in charge of both domestic and foreign policy.
It seems that message was lost on his supporters. I've seen scant evidence in interviews, polling, or personal interactions to indicate this pro-LGBTQ stance is shared.
No doubt. The Republicans have always been anti-gay. It's just that Trump done more than anyone ever has to bring them around on this issue.
I'll never forget the cheering and applause Thiel got from Republicans when he announced he was proud to be gay at the RNC. That was a pretty special moment.
He has a long record of being pro-LGBT and if he was going to backtrack on that to appease his supporters he would have done it before the election, not now after he already has their votes.