I can't help but wonder if this pivot was concocted in some right-wing think tank somewhere.
It literally was. I don't have the source at hand right now, but not too long ago there was this reveal that the modern anti-trans push with all the scientific-sounding nonsense was concocted by a specific religious group or think tank in the US. Because they were losing the anti-gay culture war, they decided on taking a different approach by focusing on a group that most people know little about: trans people. I also remember reading about how many of those transphobic "LGB" groups in the UK are being funded by religious organizations in the US. It's all part of their strategy to weaken and divide the LGBT community so that it becomes easier to pick them off one by one. Trans people are only the beginning for them. Any queer person who isn't trans and thinks they'll be safe because they aren't trans, is truly deluding themselves.